Anytime ladyparts are in the news, it’s not long before there’s a palpable feeling that longstanding norms of gender equity have been violated and that balance needs to be restored. Often, this just means getting back to the really important stuff, like whether to invade Iran, Syria or both[1]. But there’s also the point that men have parts too, and should have a share in the limelight, the same as women do when we discuss important stuff.[2]
So, I thought I’d talk about a dangly dilemma faced by men of a certain age – whether to take the PSA test for prostate cancer.
These days a lot of authorities recommend against testing. I have ignored their advice, and get tested every couple of years (news good, so far!). So, who is right? And does the argument extend to other parts and tests?
update I thought I’d add a followup question here, rather than in comments. From a decision-theoretic viewpoint, the arguments against testing imply, for consistency, the following further recommendations (subject to some qualifications I’ll spell out).
*First, that someone who takes the test (ignoring the guidelines) and comes up with a high PSA score should not have a biopsy, and should not be tested again.
*Second, that someone who has a biopsy and gets a bad result should just ignore it, and not get tested again.
The qualification is that this treats the cost of the PSA test and the biopsy (which, as discussed in comments, carries some non-trivial risks) as small, relative to the benefits of even modest changes in treatment (such as a shift from complete ignorance to “watchful waiting”). Does anyone know whether these recommendations have in fact been made? If not, can anyone provide a defence of what seems to me to be an obvious inconsistency? End update
The PSA is a test with a low rate of false positives negatives and a high rate of false negatives positives. So, if the test comes back negative, it’s unlikely that you actually have cancer. For me, that good news is certainly worth the cost to me (time and a bit of discomfort) of the test.
On the other hand, if the test comes back positive, there’s still a better-than-even chance that there’s no cancer. You can get a biopsy that gives a pretty accurate determination, and that’s what I would plan to do. Again, the value of the good news is worth more to me than the cost (more time and more pain).
The unpleasant decisions come after a positive biopsy. For those who haven’t read up on it, prostate cancer presents some pretty scary choices – untreated it leads to a painful death, while treatment is quite likely to stop your parts functioning properly in any capacity, and may not work anyway. On the other hand, lots of cancers are slow-growing and you may well die of old age before they cause any problems.
Based on that, my planned response to a positive biopsy would be to keep testing (it appears there’s some capacity to check how bad it’s getting) and change some plans that depend on life expectancy. I think the capacity to make plans outweighs the negative effects of learning the bad news.
So, if my analysis is right, I’m better off having taken the test whatever the outcome. For a decision theorist like me, that seems pretty clear cut.
What are the counter-arguments?
First up, I don’t pay the cost of the test (here in Australia, most things like that are free of charge). So, in terms of social costs and benefits, my analysis is incomplete. Still, I guess that the cost of my time and trouble is at least as much as the cost of doing the test, so the social cost is no more than double my private cost. Perhaps, if I were paying out of pocket I’d be tested a little bit less, but I don’t think that’s a big deal.
Second, some people might just prefer not to know. All I can say is that I’m not one of them – I feel more in control when I have information, even if I can’t really act on it.
Finally, and the most serious objection, maybe I won’t be able to stick to my plan of rejecting treatment if there’s a positive biopsy. In the decision theory business, we call this “dynamic inconsistency”. I hope I don’t have to find out about this, but for the moment I feel confident in my resolve.
I don’t know for sure how this translates, say, to mammograms. The official recommendations have been shifting against screening there too, raising the advised starting age from 40 to 50. But, as with PSA, it’s difficult to find a clear presentation of the reasoning behind the argument.
fn1. Logically, of course, “neither” is also an option. But let’s not be pedantic.
fn2. Irony alert off
{ 76 comments }
david 03.23.12 at 12:13 pm
Link text “low rate of false positives and a high rate of false negatives” should be reversed, to match both the linked page and the blog post. It has a high rate of false positives and a low rate of false negatives.
Mondialiste 03.23.12 at 12:16 pm
The PSA is a test with a low rate of false positives and a high rate of false negatives.
Isn’t this the wrong way round?
Roving Proofreader 03.23.12 at 12:16 pm
Your “low rate of false positives and a high rate of false negatives” link should read “high rate of false positives and a low rate of false negatives” as you know.
My father died of prostate cancer and it wasn’t pleasant. However, he was 88 at the time, and I believe part of what made it tough was the suffering caused by effects of treatment: surgery, radiation and the like. As a younger man, I’m with you on the continued testing, and I’d think more than twice about seriously invasive early intervention.
My doctor gives a PSA test every year or two. He says he cares less about how high any individual score is and more on whether it’s significantly higher than years before.
Manoel Galdino 03.23.12 at 12:20 pm
I think there is a typo here: PSA has high false positive and low false negative, right?
And good to know all of this. I’m still 31 years old, but I thought that cancer treatment would improve significantly my chances of not die from cancer, but I guess I was wrong. At least in this kind of Cancer.
Manoel
dsquared 03.23.12 at 12:20 pm
The PSA is a test with a low rate of false positives and a high rate of false negatives. So, if the test comes back negative, it’s unlikely that you actually have cancer.
Am I being more than usually braindead or have a “low” and a “high” been swapped around there?
Sonic Charmer 03.23.12 at 12:46 pm
maybe I won’t be able to stick to my plan of rejecting treatment if there’s a positive biopsy. In the decision theory business, we call this “dynamic inconsistencyâ€.
Exactly – I was going to cite this ‘dynamic inconsistency’ problem as the main hole in this analysis. In the contingent event that you get a “positive” PSA, the health institutions/doctors may (with no ill intent, of course – quite the contrary) put a type of pressure that becomes impossible to resist, to undergo treatment. At least, it takes a certain minimal fortitude to stick to your plan in the face of literally the entire health establishment dealing with you as if you have cancer and are being foolish/suicidal for not going for radiation treatment etc.
If you’re confident you have that resolve, this analysis makes total sense.
Steve LaBonne 03.23.12 at 1:18 pm
Last year I (56 years old, for context) did have a borderline PSA reading but one that had increased at a worrisome rate since the previous test, so I assented to a biopsy which fortunately was negative. I want to have all the available information, and should I ever have a positive biopsy I trust myself not to get panicked into treatment that may be worse than the disease.
Neville Morley 03.23.12 at 1:55 pm
Assuming that it should indeed be “high rate of false positives”, it’s worth noting that that is great for the individual who’s just been tested positive, but does lead to a lot of unnecessary biopsies.
kumar 03.23.12 at 2:07 pm
I’m 19 right now, I hope to be dead by 50-60 years old. I hope this won’t affect me at all.
Ray 03.23.12 at 2:10 pm
If you take the test, you are more likely to get a false positive than a true positive.
If you get a positive from a biopsy, “watchful waiting” – having no active treatment – is just as effective in preventing death as surgery or radiotherapy.
So, on the one hand, as long as you keep getting negative results, you keep getting nice bits of good news – hooray!
But if you get a positive result, you have to have more costly (social and personal) medical exam. Best case, it’s negative, and you’ve put yourself through a lot of stress for nothing. Worst case, it’s positive, but there’s nothing you can do about it to increase your chances of survival. Hello lots more stress.
So you’re picking up pennies in front of a steamroller – getting your regular small wins of “I don’t have cancer!” that will be outweighed by the hit if/when you get a positive result.
Jim 03.23.12 at 2:12 pm
Dynamic consistency. That’s the phrase. It isn’t even whether you’ll change your mind from purely internal processes. It’s that there will be outside pressure from your doctor and your relatives and friends (at least those privy to the diagnosis) to do something rather than just sit there.
All the troubles of the world stem from man’s inability to sit quietly in a room alone.
Chris Bertram 03.23.12 at 2:16 pm
Ray
_Worst case, it’s positive, but there’s nothing you can do about it to increase your chances of survival. Hello lots more stress._
But surely if you come up positive on that follow-up investigation there are things you can do (such as hormonal treatments) that do increase your chances. Or am I missing something here?
marcel 03.23.12 at 2:17 pm
Mid-50s male here.
In the U.S., the official recommendations abuot prostate-cancer screening have been changing fairly dramatically in recent years.
I haven’t bothered with the PSA/blood test because of the high rate of false positives, combined with the lack of a more accurate 2nd round test. When I turned 50, my doctor handed me a video of 2 middle aged male doctors (real ones, not playing them for the movie) arguing the pros and cons of testing. As I said, I refused it, to her (my doctor’s) evident, disapproval.[1] Now, about 5 years later, the infamous prostate rectal exam (i.e., “Let me put this glove on, now bend over and spread your cheeks…), is no longer officially recommended. Unless there is a family history of prostate cancer or some other positive indication, PSA screening is now recommended, IIRC, only for men in their 60s. Older men will most likely die from other causes than prostate cancer, because it is so slow developing. The large number of false positives combined with the adverse side effects and its slow development suggest that testing in the 50s is not useful.
There was recently (last 18 months?) report of a study from Europe, likely Scandinavia, that currently, 1 life is saved for every 40 men treated for (likely) prostate cancer. Many of the 40 experience unpleasant side effects from the treatment (impotence & incontinence are, I believe, the most common of these).[2]
Furthermore there appears to be evidence that in more than a miniscule number of cases, the body clears itself of prostate cancer on its own. That is, when prostate cancer has been diagnosed at one time, at another time later, it can no longer be found despite lack of treatment. Another reason for not testing men until their 60s.
All of these reasons, including the rapidly changing recommendations, suggest to me that I should wait several years before revisiting my decision.
[1] She clearly thinks I may have a bad attitude. When she mentioned a periodic colonoscopy, she thought that I might reject that too, i.e., that I opposed diagnostic testing in general. My understanding is that that has fewer problems identifying likely cancers, and bad consequences of treatment are less serious and less likely than with prostate cancer.
[2] Years ago, Robin Williams had a bit on olestra, where he mentioned that one of its side effects was “anal leakage”, guffawing that this should really be listed as an effect. From what I’ve read about prostate cancer treatments, these should be listed as likely effects of these treatments.
John Garrett 03.23.12 at 2:17 pm
Anybody surprised that the rate of robot prostatectomies in this country is going through the roof, and that it is one of the most profitable of all procedures (time/money) for the urologist who runs the joystick? False positive PSAs are central to this process, since the biopsy, even without prostatectomy, is profitable. And, of course, post surgery there are the all too common long term sideeffects: leaky and impotent. No thanks.
CJColucci 03.23.12 at 2:25 pm
My understanding is that once you get to be in your 50’s, as I am (clean tests so far) it’s close to even money that, if you live long enough, you’ll eventually get prostate cancer, but that you’ll likely be old enough that you’ll die of something else even if you don’t treat it. I suppose if I stay clean another ten years and am still more-or-less sexually active, I’ll be in a position where I have to seriously weigh the chance of death against the side-effects of treatment. My father got it in his seventies, got treated, suffered the most-feared side effect for the rest of his life, and died of something else at 79.
Nick Barnes 03.23.12 at 2:28 pm
If your prostate is dangly, you should definitely get it seen to.
Jim 03.23.12 at 2:37 pm
I think your decision theory is wrong, too.
Steven Wright’s great line was “You can’t have everything. Where would you put it?” It applies to information as well as physical clutter.
When making a decision you need exactly the relevant information and no more. Information which will not inform the decision is just clutter. In this case the information that you need is your age and the likelihood that even if you have prostate cancer inaction is best. Whether you actually have prostate cancer is irrelevant.
Steve LaBonne 03.23.12 at 2:44 pm
Jim, the flaw in your argument is the assumption that there is one uniform thing called “prostate cancer”. That isn’t true. How I would proceed after a positive biopsy would depend a lot on whether that and subsequent biopsies found a small, highly differentiated, probably slowly progressing tumor or one that appeared likely to be aggressive enough to greatly shorten my life. Now, predictions based on tumor histology aren’t perfect either, but they’re good enough to be worth taking into account. And thus it’s information that I would want to have.
MattF 03.23.12 at 3:13 pm
Mid-60’s guy here. PSA test results slowly increased over the years, accompanied by BPH and miscellaneous urinary problems. PSA test results eventually crossed the red line, but doctors all agreed (correctly) that cancer what not what was going on, and (arguably incorrectly) resisted the impulse to send me off to a urologist. More severe symptoms arose, led to a diagnosis of bladder stones, surgery and a prostate resection. My PSA test results have now decreased for two years in a row. In my opinion, PSA testing has been a distraction, at best.
joel hanes 03.23.12 at 3:16 pm
if you get a positive from a biopsy, “watchful waiting†– having no active treatment – is just as effective in preventing death as surgery or radiotherapy.
Unless it isn’t.
We survivors wish that my father, with early-detected and (it turned out) aggressive prostate cancer, had chosen surgery before it moved into his bones.
You makes your decision and you takes your chances.
dsquared 03.23.12 at 3:24 pm
In the U.S., the official recommendations abuot prostate-cancer screening have been changing fairly dramatically in recent years.
this (and the associated changing guidance on breast cancer) are AIUI because the state of knowledge on cancer itself has moved on. The doctors used to find lots of late-presenting cancers that they couldn’t cure and lots of early-presenting ones that they could, and assumed that there was a pretty deterministic path to the illness – ie, the earlier you caught it the better.
The current state of understanding is that actually a lot of the small tumours that they could get rid of, weren’t going to develop into big ones, and a lot of the big tumours they couldn’t cure, were of a sort that they wouldn’t have been able to do much about even if they’d caught them early. Hence, screening wasn’t as useful as it had been believed to be.
Doug K 03.23.12 at 3:54 pm
This NYT review of the state of prostration in 2009 has guided my thinking,
http://www.nytimes.com/2009/03/24/health/24well.html?pagewanted=all
It includes links to the study marcel referred to.
‘The European study found that for every man who was helped by P.S.A. screening, at least 48 received unnecessary treatment that increased risk for impotency and incontinence.
Dr. Otis Brawley, chief medical officer of the American Cancer Society, summed up the European data this way: “The test is about 50 times more likely to ruin your life than it is to save your life.‒
It seems everyone who has danglyparts and lives long enough will have prostate cancer. However just as for all my bad habits, by the time they kill me I’ll be dead anyway.. so I’m happy to wallow in my ignorance.
nnyhav 03.23.12 at 3:57 pm
JQ, you skipped a step. One that tripped me up. Some chatroom cut’n’pasting:
yes well I’m still recovering from tendonitis induced over a year ago by the antibiotic Cipro (recently black-boxed along with other fluoroquinolones by FDA for this, adverse reaction 0.3% but mostly quickly resolved, worst case spontaneous tendon ruptures, so I’m like 1 in 10,000 not 1 in a million, but it’s rare enough and not renumerative enough to have a specialized treatment regimen) prescribed to manage down high PSA (standard procedure for a dodgy test, even more recently recommended against as poorly indicative; prostate cancer may be second leading cause of cancer death among men, but for every life saved through treatment there are forty-some cases treated in which life wasn’t at stake) uncovered by routine bloodwork in my first physical in over 25 years …
not being contrary, just pointing out there’s risk in everything, over- as well as under-treatment (not that my anecdote is either)
so what’s the point? my health was compromised by what was essentially a diagnostic procedure to ascertain whether my health was compromised. I was encouraged to followup with biopsy, which I declined given the odds (approx 3-1 against any problem, longer against life-threatening, vs 5-1 against complications from procedure, longer against serious complications).
(yeah, shit happens. ageing too. muthaf…)
(and I wouldn’t have done any different above given the odds, tho I was less informed prior…)
anyway, I was married into a medical family; doctors make the worst patients, less inclined to seek treatment, at the extreme with justification:
http://zocalopublicsquare.org/thepublicsquare/2011/11/30/how-doctors-die/read/nexus/
but by the same token my ex-in-law was spared a dangerous (and rare) cancer by early (and difficult but noninvasive) detection.
so what’s the point? I dunno, serenity prayer as treatment for hypochondria? nothing wrong with being informed, fersure, but nothing’s sure, especially doctors, so go with one who’s informative, including about the uncertainties.
piglet 03.23.12 at 4:28 pm
rageahol 03.23.12 at 4:41 pm
“But, as with PSA, it’s difficult to find a clear presentation of the reasoning behind the argument.”
what the hell are you smoking? this has been the subject of endless debates between public health folks and urologists.
http://www.ncbi.nlm.nih.gov/pubmed/22203543
and you can basically look at anything by roger chou. he’s been on the us preventive services task force, and behind some of the recommendations w/r/t mammography as well as PSA screening.
just because you know something, or think you know something, if that doesn’t help to guide treatment, then the information is worthless. the fact that psa is so variable, and that in order to confirm you have to have a biopsy anyway, and that on a long enough timeline every male will get prostate cancer, well, just read the damned articles. my interpretation is that PSA screening is pushed largely by urologists because they make money off of a test that is at best inconsistent.
also, too: http://www.ahrq.gov/clinic/pocketgd1011/gcp10s2.htm
piglet 03.23.12 at 4:48 pm
I now think that the terminology has become confused. The false negative rate in the scenario would be 25%, not 1%. So it’s actually quite high. Somebody correct me if I’m wrong.
piglet 03.23.12 at 4:54 pm
From the CDC guide (http://www.cdc.gov/cancer/prostate/pdf/prosguide.pdf), p. 10:
Bruce Wilder 03.23.12 at 6:16 pm
Chris Bertram @8: “But surely if you come up positive on that follow-up investigation there are things you can do . . .”
And, there is the rub: “surely”
There are things that you can do, but none of them are likely to improve your quality of life, or even extend your life.
Treating the maladies of aging, or even the maladies of a life of bad habits, can be extremely hazardous, especially when we are talking about “emergency” interventions such as surgery, against something scarily acute, like cancer.
The sad thing is that there are people, who will have a prostate cancer, which metastasizes and kills them, tragically young. But, the vast number of people, who will be diagnosed, as a result of mass screening after a certain age will be harmed more by the surgeries and other treatments, than they would have been by prostate cancer.
Barry 03.23.12 at 6:18 pm
“So, I thought I’d talk about a dangly dilemma faced by men of a certain age – whether to take the PSA test for prostate cancer.”
Quibble – it’s not dangly, it’s all up inside.
piglet 03.23.12 at 6:53 pm
One source, http://mensnewsdaily.com/archive/w/wascher/03/wascher072703.htm, claims a PSA test false negative rate of 30%. Another source, http://www.mayoclinic.com/health/prostate-cancer/HQ01273, states without quantifying the false negative rate that “Some prostate cancers, *particularly those that grow quickly*, may not produce much PSA”. Still another quantifies false negative rate at up to 15%:
John Quiggin 03.23.12 at 7:38 pm
Apologies to everyone for reversing the negative and positive. I even looked at it, but I seem to have a mild disability in that respect, as this happens fairly often.
“if that doesn’t help to guide treatment, then the information is worthless” – that’s the way doctors typically reason, and it’s wrong. Information on my life chances is valuable to me, whether the news is good or bad. So, a better restatement of my observation about the lack of clear reasoning would be
rageahol 03.24.12 at 5:45 am
“information” on your life chances is valuable to you, even if it’s unreliable?
why not just cast runes then?
rageahol 03.24.12 at 5:52 am
sorry for the double post.
if you get information about your life chances that:
1) is not independently verifiable in some way (i.e. falsifiable) and
2) cannot guide treatment (because e.g. there is no differentiation in first-line therapies based on this information)
then does that non-actionable information even qualify as scientific?
T 03.24.12 at 6:29 am
Family history should come at the start of this. As a 40-something male whose father and three of his four brothers all had prostate cancer (2 of the 4 very aggressive types), I’ll keep getting PSA tests. They can’t worry me much more than I should already be concerned.
One more factor in the decision making comes in after a positive biopsy. The Gleason Score is important. See http://en.wikipedia.org/wiki/Gleason_Grading_System. My dad’s PSA had been creeping up and biopsy revealed he had a Gleason 4+5. That’s just about top of the scale. He went for the radical robotic prostatectomy and it was probably the right decision. First post-surgery PSA test was close to zero/negligible so we hope it hasn’t spread. One brother went with radiation and hormone treatments, but it is all through his spine now.
Ironically, his biopsy was delayed quite a bit (which in his case with an aggressive tumor was most definitely not good) because his urologist was incapacitated for a while recovering from complications and infection from his own prostate biopsy. So, also factor in possible complications related to biopsy as a cost.
Chris Bertram 03.24.12 at 7:29 am
@BruceWilder … yes but specifically, I mentioned hormonal treatments. I don’t see this as having destroyed quality of life in the one case I’m familiar with.
PaulB 03.24.12 at 7:40 am
It’s easy to be nonchalant about the effects on you of a positive test, until it happens. I suspect that for most people knowing that they have low-grade prostate cancer which they’re leaving untreated makes their life worse. A lot of patients opt for prostatectomy, presumably because they prefer sterility and the risk of impotence and incontinence over the strain of doing nothing about their cancer.
John Quiggin 03.24.12 at 7:51 am
@rageahol All information is unreliable, and this is trivially true for info about life chances, which could be ended by a car-crash on any day. Still, AFAICT the PSA+biopsy combination gives you pretty good information about whether or not you have a prostate cancer. That’s fairly significant information
John Quiggin 03.24.12 at 7:52 am
@PaulB You’re right, but this still makes the official advice rather problematic since it comes down to “this information could be useful to you, but we think you’ll react unwisely to it, so we recommend you don’t get it”
PaulB 03.24.12 at 8:58 am
I think there’s more to it than that. It might be wise to have the prostatectomy if the mental strain of living with untreated cancer is too great. But wiser still not to find out in the first place.
L File 03.24.12 at 11:38 am
Don’t discount the risks involved in the biopsy either. I had mine at a very high class clinic in Switzerland and then spent four days on an antibiotic drip clearing up the infection that resulted. Prostate infections can be life threatening – as mine surely was even in a top notch facility – and should not be taken lightly. Statistics for complications in biopsies are over 1% I believe.
Biopsy was negative.
lff
Barry 03.24.12 at 12:18 pm
John, I just realized that you were discussing testing and such without mentioning getting permission from the wife or appropriate legislature/religious organization :)
herbie 03.24.12 at 1:38 pm
I had a high PSA at age 42 after a rectal exam indicated slightly enlarged prostate. After the biopsy came back positive all my intentions of carefully weighing my options immediately and irrevocably flipped to “get that thing out now!”
I shopped around for a good surgeon that had done thousands of prostatectomies, doing fine three years out, all parts still working.
I learned that for me it’s either ignorance or immediate action. Also, even though (or because) I’ve been a robotics engineer, I will choose a surgeon over a machine.
Hank 03.24.12 at 5:06 pm
At 55 I put myself forward for screening. PSA around 4.8 ng/mL. Called in for a biopsy. Prostate perforated through rectum 10 times, then a week on antibiotics. Spectacularly colorful pee.
Letter comes. “Nothing detected..” (detectable note of disappointment) “… please come in for another”. Same deal. Another 10 perforations. Horrified various individuals standing downstream of me in the pub lavvy.
I then made some study of the prostate, the test, the prognoses, and. I discovered that PSA levels can depend on your level of sexual activity. I have next to none. Shortly before my next PSA test, I took certain measures. Next PSA level, about 3.4 ng/mL. Again, the tone of disappointment in the letters. Next time, same measures, even lower result. Eventually, they gave up.
I can’t help thinking that the tone of disappointment was because I was slipping out of their claws. I now feel very sceptical, or at least ambiguous about epidemiologically based screening. (I had several to fill out pages and pages of idiotic forms about my not very colourful life-style.) I’m not sure how I would have felt had things turned out otherwise. But I think I men should be aware of certain basic facts about this bit of their body. Nobody tells you these things. A biopsy is not a triviality (except to people who administer these things 16 times a day.)
marcel 03.24.12 at 5:40 pm
In the spirit of Barry’s comment, I offer this link.
marcel 03.24.12 at 5:41 pm
Er, this link: http://funnyemail.org/2009/04/the-danger-of-dangling-participles/
Billikin 03.24.12 at 7:43 pm
One thing that changed my mind last year is that treatment seems to affect survivability 10 years out. Prostate cancer is slow growing, so if your life expectancy without it is longer than a decade, it is probably a good idea to get tested. :)
Tedra Osell 03.24.12 at 8:23 pm
All I can add is that every man over 60 I know has had prostate cancer. My father and father-in-law both had it treated and are fine. A friend had a worse case, had a rather, uh, extreme operation and chemo, and is fine. My grandfather, who was a GP, was diagnosed at 70, if memory serves, had surgery but opted to forego chemo, and died of it. But he knew what he was doing and I think that his decision to avoid chemo at that age was probably sound. He had hospice in, and though of course dying isn’t great, he had tons of morphine and no pain as far as I was aware.
IOW, I say test.
Bruce Wilder 03.25.12 at 12:04 am
Quiggin @ 31 restates as, “The analysis presented to support the recommendations makes sense from the perspective of someone running a health system [but] it’s not presented in a way that helps me to determine whether the costs for me exceed the benefits”
It seems to me that the upshot is that the “someone” with perspective cannot write reliable rules for clinical practice, so clinical practice will not follow reliable rules. You cannot determine the costs and benefits, because key technical problems have not been solved — as a general proposition, the “production process” has to be under technical control, before there are costs and benefits to weigh. As it is, you would be acting under a regime of genuine uncertainty, where there’s no well-behaved probability distribution, and, therefore, no reliable assessment of risk or treatment options.
I suspect it is a general problem in medical care, and a major cost driver, as well as a reason why medical care has been moving fitfully from a personal craft toward bureaucratic management, for the last 75 years or so.
greatferm 03.25.12 at 2:10 am
I’m 76. I personally do not give a shit what “studies sayâ€. My health is my health, and I prefer to get individual data, study my personal situation, and decide accordingly.
When my Doctor told me my PSA had spiked higher, she referred me to a urologist, who persuaded me to have a biopsy. Scary prospect, you hear all sorts of stories about how uncomfortable it is, but he was very good. I have had much worse experiences in the Dentist’s chair.
He did 12 samples, and 6 were positive, all on one side.
Off to the cancer center for 35 sessions in the rotating radiation machine, 7 weeks x 5 days. Comfortable, unless you are sensitive about being naked.
All fixed now, 4 + years, and sort of a rejuvenation. Everything works, and better. I still get the PSA test annually, will continue to get it, Kaiser will provide it, and it they didn’t, I would pay for it, and it continues to be miniscule.
Most interesting side-effect during treatment was the testosterone-suppressing shots, two of them, which were explained to me as increasing the success of the treatment from 85% to 95%.
The psychological effect was striking. A heightened awareness, my thinking became sharper, quicker, more perceptive, more articulate, Listening to a symphony, I could pick out the individual instruments. This seems to have continued.
rf 03.25.12 at 3:47 am
I might be missing something but I’ve seen a lot of people get ‘good time’ from treatment. And have you factored in all the outside sources of pressure that are brought to bear at a time like that, namely the peace of mind of those closest to you? The things you can’t possibly know about a subject that is outside your area of expertise? How you might feel about your decision ten years on? How you might respond to the treatment? The ‘unknowns’ underpinning the entire enterprise.
As someone that gets tested twice a decade for a genetic defect I know I don’t have and that probably can’t be diagnosed in any definitive way, I personally don’t think that it boils down to an easily definable ‘decision theory’ model. How can it be defined on such unrealistic terms?
If no one can deal honestly with Chris’s question about hormonal treatment or speak professionally about the multitude of options available, then surely Tedra’s advice to err on the side of caution, if this is her advice, appears the best option?
rageahol 03.25.12 at 4:20 am
One of the major confounding factors here from all the anecdata supporting the “treatment = increased survival” formulation is the fact that we simply do not know what determines whether a cancer will kill you or whether it can be handled by the immune system for the next 20 years. This is a particularly large issue with both breast and prostate cancer.
so, no, that treatment very possibly (i would say probably) did not save your loved one’s life, unless it was already at the stage when you just have to pray. The cancer may have gone away, but in many cases the odds are good that it would have done that anyway.
the fact that we are finding neoplasms earlier does not mean that all of them we find will develop into life threatening cancers. so that treatment that made shit of your life for a year or two, and left you incontinent? it is reasonably likely that that was totally unnecessary.
that’s why screening is not endorsed by the USPSTF. It’s definitely something you should talk with your physician about, but a whole lot of physicians are resistant to this idea as well, so it’s not like you’ll necessarily get a straight answer from a clinician either. it’s a problem, because like climate change, the science behind it is strongly supported by the evidence, but some people simply refuse to believe it.
more screening is not necessarily better. in fact sometimes it’s worse.
derrida derider 03.25.12 at 4:49 am
“I’m 19 right now, I hope to be dead by 50-60 years old.” – kumar @9
I remember deciding the same way at age 19, and now I’m in my 50-60s. Believe me, there is a dynamic inconsistency here.
There’s one huge plus to getting old, kumar – it definitely beats the alternative. Loss of dangly function would be a heavy blow – no doubt about it – but it’s still a lot better than death.
derrida derider 03.25.12 at 4:51 am
PS – where are the Crooked Timber women in this thread? We guys have never hesitated to put our tuppence worth into any comments threads about ladyparts – you ought to reciprocate. Speak up.
Bruce Wilder 03.25.12 at 6:08 pm
dd: “Loss of dangly function would be a heavy blow – no doubt about it – but it’s still a lot better than death.”
You will die, regardless. Loss of dangly function is an option. Not an attractive one, for myself. ymmv
Barry 03.25.12 at 6:09 pm
you wish :)
bianca steele 03.25.12 at 6:40 pm
Still, AFAICT the PSA+biopsy combination gives you pretty good information about whether or not you have a prostate cancer.
I really don’t want to jump in with an extraneous topic, but I don’t think the same is true of mammograms for younger women (firm tissue doesn’t x-ray well)–the initial test is more likely to be “inconclusive” or “ambiguous.” So it might not be the case that the reasons for changes in the recommendations are the same.
magistra 03.25.12 at 7:01 pm
Since you wanted more women to comment , and thus introduce some rational thought into the whole process ;-), it’s interesting to compare death rates for prostate cancer for the US (where screening seems to be commonplace), and the UK (where it isn’t standard practice. The death rates per 100,000 given by this site are 8.2 for the UK and 6.1 for the US. Now there may be skewing effects for different effectiveness of treatment (US healthcare generally being far more variable in quality than British), and there may also be genetic/social differences between the two countries affecting the likelihood of developing that particular cancer, but it does initially suggest a very minor longterm effect of screening versus not-screening.
Chris Bertram 03.25.12 at 7:30 pm
Magistra thanks. The table you link to is very interesting. Where people overwhelming die younger of something else then the proportion of deaths from prostate cancer is going to be smaller, and that’s what we see. But there seem to be fairly big differences among fairly similar developed nations. Southern Europe looks much lower than Northern Europe (and generally lower than the US, with the UK in the middle). The Nordic countries look pretty high. [And weirdly, the Caribbean looks like the prostate cancer death zone].
Emma in Sydney 03.25.12 at 7:57 pm
Is there a reason why comments from me and one other woman, which appeared last night, are now deleted?
Cranky Observer 03.25.12 at 8:04 pm
Emma @ 7:57: there was a site outage around 1800 UTC on 25 Mar that, from the error messages I received, may have involved database failure. I imagine those comments were simply lost.
Cranky
Chris Johnson 03.25.12 at 8:29 pm
I’m a physician, but do pediatrics, which means I know little more about the prostate than exactly where it is. But the PSA issue is not unlike the one we face with many other medical tests: bad or confusing information is worse than no information. It’s a well-known phenomenon that one marginally indicated test often leads to a borderline finding, which, in turn, leads to other tests, which also have a risk of being borderline, leading to more tests. And so on. Eventually somebody wants to get invasive just to settle the matter. Testing has risks, and not just from the test itself (e.g. radiation from a CT scan). Since the PSA is a blood test we think of it as a simple, risk-free thing to do. It’s not.
FWIW, I’m 60 and my internist recommended a PSA, which I got. It was low. Like upthread commentators, in my own case I thought I could process the information and use it reasonably. But I’m staying away from urologists as long as possible. Their general bias is to intervene. It’s a little like taking your child to an ENT surgeon following several strep infections and asking if the tonsils should come out — odds are that is what they will suggest. They’ve got a hammer, and you’re a nail.
Emma in Sydney 03.25.12 at 10:03 pm
Here’s my earlier comment, about deleting comments, which was itself deleted. Automagically. It’s all getting a bit meta.
Emma in Sydney 03.25.12 at 9:20 am
@derrida derider, “Where are all the Crooked Timber women in this thread?”
Speaking for myself, I’ve typed a couple of comments on this thread, and then said to myself, ‘you know, Emma, it’s nothing to do with you. Men are capable of making their own decisions without your input’. And deleted my comment without posting. Very freeing, really.
Chris Bertram 03.25.12 at 10:09 pm
Emma: no comments from you in “Trash” or in “Spam” at the CT server, so no-one has deleted you. Maybe a software glitch.
JanieM 03.25.12 at 10:15 pm
There was a period of a few hours an evening or two ago when I couldn’t access CT. Then it was back again.
There was another such period this morning, followed by a short stretch where everything seemed normal again and people were commenting. Then: more hours of no response except server error messages, and even one message from I-forget-which-hosting-entity asking for a log-in.
I’d guess that all the comments entered during today’s “normal” interim between periods of down time are the comments that are now missing. “Software glitch” sounds about right.
UserGoogol 03.25.12 at 11:14 pm
People have already commented on it, but to phrase my comment in the form of a dumb joke:
If your prostate is dangly, you should see a doctor right away.
PaulB 03.26.12 at 6:03 am
The mortality rates magistra linked to look too low to me, though the ratio may be about right. This paper is informative about the US/UK comparison. (I suppose magistra’s figures may be deaths per 100,000 population, rather than per 100,000 men, which would explain some of the difference.)
There’s a problem with comparing mortality data, in that cause-of-death recording may not be very reliable. Perhaps the doctor responsible will put prostate cancer down as a contributory cause of death if the treatment chosen had been “watching waiting”, but would not do so for an otherwise identical corpse who’d had a prostatectomy.
Here‘s the Cochrane review of PSA testing.
If you get advice about PSA testing from a doctor in the USA, you might want to be aware of this case.
Katherine 03.26.12 at 1:25 pm
Like Emma, I thought – nah, it’s not my parts being discussed, all I would do is be ignorant and asking annoying questions betraying my ignorance of the actual experience. It would be just lovely if that impulse could be reciprocated.
That said, good luck to all making these decisions. It does seem a bit rock-and-a-hard-place. My father-in-law recently had a biopsy. Came back negative, and I’m sure he didn’t enjoy the experience – I’m equally sure he’d rather have had the information than lived with not knowing one way or another.
piglet 03.26.12 at 3:12 pm
JQ, what do you consider a low false-negative rate? Anything below 50%? I don’t think that statement is correct and stating that, without qualification, as a fact in a public-health related post seems dubious to say the least.
michael e sullivan 03.26.12 at 10:15 pm
This seems like fairly straightforward decision theory. I see two reason why it would not make sense to take the test, given a high enough false positive rate. One is that treatment of a surely identified cancer is almost always an iffy enough decision already that knowing you have it isn’t all that important. Two is that the further testing required to determine whether you have cancer with more certainty is costly or dangerous.
My understanding is that biopsies are dangerous. Not dangerous like surgery, but they do carry risks and side effects that may be out of proportion to the information gained. That would suggest that having already taken a PSA and gotten a positive would not mean that you necessarily shouldn’t get a biopsy, but it certain does mean that you probably shouldn’t if there is nothing else affecting your probability of having cancer.
OTOH, if a biopsy or whatever other further tests are fairly definitive (at the end of it, with positive results, you can be 95-99% sure you have cancer), then the fact that you shouldn’t have started testing in the first place, doesn’t really make any difference to your further decision of whether or how to treat.
Consider a purely mathematical model that has limited relationship to reality. Suppose that if you have prostate cancer you have a 20% chance to die N years earlier than normal if untreated, and 15% if treated optimally, but a 50% chance of negative side effects in either case. For treatment of a known cancer, you would balance the risk of side effects against the risk of death. Now suppose that you decide that in this case you would choose to treat as long as it reduced you risk of death to 16%, but not 17%. This makes treatment a quite marginal decision, but you would choose to treat.
Now let’s consider the decisions at earlier points. Suppose a biopsy will absolutely confirm whether you have a cancer or not at a 10% risk of side effects equivalent to the treatment’s. And suppose that initial low cost low risk test has a false positive rate such that if your reference class is all men >50, a positive test means you have about a 20% chance of having the disease.
Well, if you biopsy, how much does this reduce your risk of death? 20% of the time, you reduce your risk of death effectively from 16% to 15%, and 80% of the time, it does nothing. You’ve decided in your treatment decisions that a 50% risk of side effects is about equal to a 4% risk of death. If this relationship is roughly linear, then a 10% risk of side effects is worth .875% risk of death.
If we calculate everything in terms of deathriskEQ%, then 80% of the time, you increase your DREQ by .875% and 20% of the time you reduce it by 1%, which is not a very good trade. On average, having the biopsy increases your DREQ by .5%.
So in this instance, you shouldn’t get the biopsy, but if you had already had one and it was positive, you *should* treat the cancer.
I have pulled these numbers out of my rear, but they are intended to show that it is not logically inconsistent that you should not take the test, but having done so anyway, you should treat the disease.
The medical recommendations may be including an assumption that people who test positive will get a biopsy even when it is not warranted, and if so, it may make sense to take the test, but taking the test *still* would only make sense if you understood when the biopsy would be warranted based on narrowing your reference class, or deciding on test results that include more information than positive v. negative.
Peter 03.27.12 at 9:54 am
Hi,
I feel I should add my 1/2p’s worth to the debate you have initiated on whether to test for prostate cancer (PCa). First, I should state my background and possible prejudices. I am an academic in the social sciences and in my discipline we are aware of and occasionally use decision trees.
I was diagnosed 4 years ago with asymptomatic PCa as a result of being part of the ProTecT study–a very large scale trial of the efficiency of the PSA test. As part of the study, I had my PSA — taken twice — followed by a biopsy that revealed ‘medium risk’ PCa (this was a Gleason score of 7 (minimum score = 2; maximum score = 10) based on a visual examination of the 10 prostate samples.
So I have been through the decision process you envisage following if your PSA should put you in the ‘at risk’ region.
You should be aware that PCa currently kills 10 000 men a year in the UK and is diagnosed in 30 000 men every year. It is now (or soon will be) the number 1 type of cancer in men (taking over from smoking, as the numbers of smokers declines).
About 1-in-12 men will be diagnosed with PCa over their lifespan. Most men will be diagnosed later in life, with the incidence of the disease rising with age, typically from 55-60 onwards. (I was in my mid-50s when diagnosed–so this has both influenced my decisions and possibly how I view the problem and issues.)
I have also read a lot of the recent clinical studies on the effectiveness of PSA as a ‘screening’ test which are referred to in some of the comments to the post.
Turning to the decision theoretical approach that you advocate.
First, generally speaking, if the test is negative, then there is no problem. Although, as recent research is showing, the old guidance on what constitutes negative is continually being revised down. Under the guidance that prevailed when I had my research-led PSAs, I would have been deemed healthy! So the cutoff is important. Further, other factors can influence the test results: PSA rises with age as the prostate generally enlarges and there are a number of conditions (or actions!) that can also raise the PSA level. One test is therefore inconclusive unless it is very significantly above average (say over 10).
Now what to do if you have a worrying PSA. Well, clinical procedures are evolving in this area (I belong to a PCa support group and take part in a discussion group with the local NHS here on improving patient and clinical processes) . First, it is now possible to use MRI imaging to help identify if the prostate is cancerous. This may therefore preclude the need for a biopsy as a first step; or if one is carried out, allow a more accurate targeting of the procedure. Note that a biopsy is pretty much the only way to identify whether there is PCa or not.
Let us now say that cancer is prevalent and the pathologist reports a Gleason score of 6 (medium risk, under the NICE guidelines) so that there are a range of treatments available, including active surveillance (watchful waiting).
First, clinicians will point out that the chances of successful outcomes improve if the cancer is treated at an early stage. This is the genie that testing has thrown up and which the post rightly identifies. A lot of men are going to die of other causes rather than PCa. Partly this is due to the fact that the disease is age-related and partly due to the fact that some tumours are ‘grumblers’ and only develop very slowly.
Problem here: the current state of knowledge on PCa is such that there is no ability to distinguish the virulent from the slow growing cancers. So you have to gamble based on what you think.
Second issue: as a precaution clinicians will advocate early treatment. With a Gleason of 6, taking surgery as the treatment option, you are likely to achieve a full eradication in 4 out of 5 cases. Good odds, given it is cancer!
However, these odds decline dramatically if you postpone treatment and have advanced PCa.
OK, happy to adopt a wait and see attitude. However, this exposes you to another uncertainty or the unpleasantness of repeated biopsies (whose long term effects are unknown). Changing levels of PSA might be due to random factors or are indicative of spreading cancer. As long as the PCa is confined within the prostate, you are OK, the moment it spreads beyond this point, you have few good treatment options.
Advanced metastatic PCa seems quite rapid in its effects and certainly is likely to kill the majority of men within 5-8 years.
There are other issues: If you are diagnosed with PCa and the medical advice you receive is to opt for early treatment, will you ignore this advice? I think an analogy is needed here. What if there was a test which identified that you had a heart condition that could–in certain circumstances–lead to heart attacks. However, the test is imperfect and the treatment involves a type of treatment that has a significant risk of leaving you partially physically disabled. Would you opt for it?
What about the decision theory approach for PCa, then? Let us take a 60 year old person who has a Gleason of 6. The life expectancy of a man at 60in the UK based on the latest statistics is 22 years (or so). So now we have the problem of estimating how long the identified PCa will not become metastatic. We know that metastatic disease will likely kill in 5 years–so at 60, you have to be confident that the disease will not develop within 17 years for you to be no worse off. Umm, many, many uncertainties here. Factors which might influence the decision include race, relations who have been identified with PCa, your general physical health. Your attitude to risk, etc., etc.
This becomes a difficult choice–medical advice is to seek early treatment–waiting, as Steve Jobs of Apple did with what I understand was, when diagnosed, a treatable disease–involves significant risks to longevity.
What decision model should you use to address this? Minimax, Decision Regret, etc.? These will lead to different decisions.
In my view, the whole decision theoretic approach is flawed in this situation. First, there is the debilitating situation of not opting for treatment knowing that you are living with a ticking time bomb within you that, like the ‘Pass the Bomb’ game, can explode at any time. Are you happy living like that? My experience from talking to those who have opted for this is that it is untenable long term and — of itself — could create health issues due to stress, etc.
Note that monitoring is looking in a rear-view mirror with many uncertainties in terms of how accurate a picture it is providing. You only need a small amount of spreading to render all current treatments ineffective.
Second, the uncertainties are huge in this decision. We simply do not have the data concerning the pathways that an individual’s PCa will follow. So you are gambling on a hunch (the medical profession cannot advice you on this at present and based on their training will be openly or subtly pushing for early intervention).
So my take on you post is as follows: first the evidence for PSA testing as a good screen to deal with the disease is poor. The largest and best studies indicate no improvement in survival rates–or very modest ones for the costs and downsides of overtreatment.
So why get yourself tested? I think the only rationale is the opposite of your conclusion. If you are identified with early stage PCa you absolutely opt for early treatment. What you are doing with PSA testing is rubbing the genie lamp: if the genie appears, you have got to respond to its wishes.
Otherwise, best leave the lamp alone and not ask the dark question.
Should add that this is an exceedingly good discussion .
Peter
Anthony 03.27.12 at 7:36 pm
It seems to me that the logical thing to do would be to have a baseline PCA test in one’s mid 30s, and occasional (every 3 – 5 years?) PCA tests thereafter until about age 60-65. After all, even a slow-growing tumor at age 45 is a bigger problem than the same one at age 65, and the impact of intervention is greater because of the greater life expectancy otherwise.
Peter 03.28.12 at 3:11 pm
Anthony,
Indeed, the older you are the less logic in being tested. I have met and talked to (we provide 1:1 support to newly diagnosed men) in their 70s who have had their PSA tested, found high and then biopsied and found to have medium risk PCa.
The pressures on these men to have treatment is intense. Their partners are hearing the ‘C’ word and want action now!
For these men, it is questionable whether treatment will have any benefits–but treatment is highly likely to have significant consequences, either incontinence or worse. (I think our group find the complication statistics far underestimate the likelihood of post treatment problems. Partly, because they are vague and hence go under reported and/or men tend to play them down.)
Peter
John Quiggin 03.29.12 at 10:09 pm
@68 The linked text gives an unconditional false negative rate of 1-2 per cent. Conditional on having cancer, the rate of false negatives is around 25 per cent. That is (according to the link) conditional on receiving a negative test, your probability of having cancer drops from 4 per cent to 1 per cent. I’d regard that as a low rate of false negatives.
Peter 03.30.12 at 9:50 am
We need to consider, as the following quote from a discussion in the New England Journal of Medicine in connection with a large randomised trial of screen (via PSA) and non-screen, indicates between diagnosis and treatment outcomes:
DR. McNAUGHTON-COLLINS: ‘I think that there is convincing evidence of harm, to answer your question, Tom. The two studies together show marginal to no benefit across several years of follow-up at the cost to so many men of overdiagnosis and overtreatment. So that deceptively simple PSA test inevitably leads to a cascade of biopsies, which lead to prostate-cancer diagnoses, leading to aggressive treatments for those prostate cancers, leading to men having substantial side effects from those treatments, urinary incontinence, sexual dysfunction. And the problem being that, for many of these men, they suffer those downstream troubles for a cancer that was never, ever destined to cause them harm in their lifetime.’
[2009 Massachusetts Medical Society]
This neatly summarises the real issues and hence whether the incidence of false negatives, is not really the issue .
Peter
John Quiggin 03.30.12 at 10:03 am
To repeat myself, though, the problem seems to be with the biopsies or the treatments. So, do the relevant authorities recommend against biopsies for those with high PSA or against treatment for those whose biopsies indicate cancer? If not, isn’t the problem with the authorities rather than with the screening?
Peter 03.30.12 at 11:15 am
John,
You state that ‘the problem seems to be with the biopsies or the treatments’, not sure I follow this line of argument. The problem arises from the fact that PCa is a varied cancer (as I suppose all cancers are) but that the diagnostics are such at present that the clinician cannot distinguish reliably the two kinds. The Gleason score is a 5-point scale where the prostate biopsies are compared to a set of typical scaled prior examples of PCa cells, starting at 1=0 normal and 5= highly differentiated. This is based on a visual examination and hence the experience of the pathologist in the test. Whether something is a 1 or 2, or whatever, is ultimately a matter of a degree of subjectivity. Yet, the implications are quite severe; a Gleason of 5 (3+2) is quite different in treatment recommendations than a 7 (4+3)!
Then there is the problem of disease evolution–this is poorly understood at present–where under current clinical thinking, it is better to act early, as I mentioned in my post, due to the better outcomes than wait and see, where waiting can lead to untreatable disease.
The evidence from the two largest studies to date, which are reported in the New England Journal of Medicine on PSA screening is that it has very little impact on life expectancy. But the problem with screening is that, once a man is identified as having PCa, it leads to the likelihood of treatment. You have to be very bold and/or informed to go against the current views of clinicians. You are pitting your information against their (superior) information. Not for one minute do they think they have it right–there is a lot of research out there on this at the moment, but it will be a very long time in providing the answers–but based on their current understanding of the disease, available treatments, clinical studies, and personal experience, they will advocate what they see as the best option. In many cases this will lead to treatment, either as they recommend it, and/or because the patient wants it (a doctor will never refuse to treat a patient in these circumstances, even if they have reservations about the clinical benefits: it’s not their life, but the patient’s that is at risk). Hence the overtreatment which occurs and which is leading a significant number of men to suffer quality of life issues.
I think the figure — without checking — is that 64 men will need to be treated to save 1 life. Not good odds, really and a major problem for clinicians.
Peter
Comments on this entry are closed.