Ignore Prostate Cancer

A US task force says don’t bother with prostate cancer tests:

The blood test that millions of men undergo each year to check for prostate cancer leads to so much unnecessary anxiety, surgery and complications that doctors should stop testing elderly men, and it remains unclear whether the screening is worthwhile for younger men, a federal task force concluded yesterday. …  The 16-member U.S. Preventive Services Task Force … published the new guidelines today in the Annals of Internal Medicine. …


Each year, prostate cancer is diagnosed in more than 218,000 U.S. men. About 28,000 die of it, making it the most common cancer and second-leading cancer killer among men.  The PSA test, which measures a protein in the blood produced by prostate tissue, has significantly increased the number of prostate cancer cases being diagnosed at very early stages. …

Many men experience stressful false alarms that lead to unnecessary surgical biopsies to make a definitive diagnosis, which can be painful and in rare cases can cause serious complications.  Even when the test picks up a real cancer, doctors are uncertain what, if anything, men should do about it. Many men simply are monitored closely … Others undergo surgery, radiation and hormone treatments, which often leave them incontinent, impotent and experiencing other complications. …

Since the task force issued its previous recommendations in 2002, at least eight new studies have been published. Among them was a large Swedish review that found that men age 65 and older who were treated for prostate cancer were no more likely to survive than those who were not. …

Others were highly critical, noting that prostate cancer death rates have plummeted in many countries after they instituted widespread PSA screening.  "We have seen a dramatic drop in mortality," said … a spokesman for the American Urological Association. "They’re not paying attention to that."  Others objected to setting an age cutoff, saying men should be evaluated individually.

Here the usual medical debate is repeated.  One side says specific studies find no benefit, while the other side says falling mortality must be due to medicine, and we must treat patients as individuals, not like groups as in those studies.  Alas hope, deadly hope, springs eternal. 

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  • http://profile.typekey.com/RobinZ/ Robin Z

    Isn’t “the experts are wrong, wrong!” a standard news bias? I’m not sure we can conclude much of anything from just one article.

  • retired urologist

    Screening for prostate cancer is a consumer-driven activity, rather than a science-driven one. When PSA testing was developed, both doctors and the public believed that low levels meant absence of CA, and high levels meant presence of CA. In reality, when sextant biopsy is performed on men with either PSA of 0-4, or PSA 4.1-10, the incidence of cancer is only 6% less in the first group (which is supposed to be normal) than in the second (which is supposed to have CA). In addition, in men in their fifties with 0-4 PSA and a positive biopsy, the cellular morphology tends to be worse, and many already have metastasized (cannot be cured). In autopsy studies of men in their 80’s and older, having died of something other than prostate CA, over 80% were found to have microscopic evidence of prostate CA. In other words, if you live long enough, you’ll have it. Yes, there are 25,000+ deaths annually in the USA from prostate CA, but the chance of dying WITH prostate CA rather than FROM it is orders of magnitude greater. By definition, those patients who are candidates for radical prostatectomy have no symptoms, while approximately 100% of those who undergo the surgery have loss of some desired function. If the surgery (or radiation) saved a life, there could be an argument for it. As it is, the survivals are almost the same, with or without treatment (an exception is a younger man with severe cellular morphologic changes and no metastases; a quite unusual situation). Since virtually every man on Medicare has a reasonable chance of having prostate CA, routine PSA and biopsy tests are contributing to the impending bankruptcy of the system, without adding to survival.

    PSA specificity
    prostate CA screening
    criticism and reply

  • Alan

    The statement that prostate cancer death rates have plummeted in many countries following the institution of widespread PSA screening looks susceptible to the post hoc fallacy.

  • http://hanson.gmu.edu Robin Hanson

    retired, thanks for the expert commentary.

  • http://profile.typekey.com/halfinney/ Hal Finney

    I had a run-in with a high PSA count a few years ago – had to have several prostate biopsies, quite painful and unpleasant. Luckily it came to nothing, apparently just a case of local inflammation, and my PSA is back down now. This new information will certainly make me less likely to accept medical treatment if it goes back up.

  • http://current.pic.tv Colin

    I wonder when the experts are going to really figure this issue out. Test, don’t test, test, don’t test. I’m still younger, so I’ll get screened in a few years. I’d rather know if I have a choice.

    We wrote a post trying to explain this today at http://current.pic.tv/2008/08/06/no-prostate-screen-for-old-men/

  • curtadams

    I suspect this is just an underpowered study. Here’s a different study from Austria showing not only did prostate cancer deaths plummet with the introduction of aggressive prostate screening, they fell much faster than in regions of Austria which didn’t have aggressive screening. http://www.sciencedaily.com/releases/2008/04/080422112950.htm All-cause mortality is generally almost useless unless you’re dealing with heart disease, because the effect you’re looking for (reduced prostate mortality here) disappears in the noise of all the other causes of death. In addition, there’s a major confounding factor in that patients who get treated are more likely to have dangerous cancers – they’re a higher risk group than watchful waiting. So the Swedish study is saying a higher-risk group that received treatment doesn’t do measurably better than a low risk group, using a poor measurement system. Pretty flimsy stuff to stake thousands of lives on.

    A 7% annual drop in death rates is far too much to just be happening. A plausible alternative hypothesis for reduced prostate cancer deaths has to include a model of why this is happening, and it has to be a testable model.

  • Jor

    It might helpful to read the actual guidelines — which actually isn’t a major change from the old ones. Patients with a life expectancy of less than 10 years probably don’t benefit from prostate cancer screening because it is unlikely that prostate ca. is what will kill them. What is new in the guideline is that “less than 10 year life expectancy is hard to figure out”, so AHRQ made it simpler, and just said no point in screening men over 75.

    Hal, if you are young (i.e. not a senior citizen) — I don’t think its prudent to ignore screening (esp. if you have symptoms). _Most_ cancers are curable if caught early — with prostate cancer being the most controversial in terms of treatment efficacy because so many men will develop it when they get older and it will not be what kills them. A helpful way to tease out how beneficial an intervention is going to be is to ask a doctor in a straight-forward manner, “how likely is this going to be what kills me?”

  • http://www.iphonefreak.com frelkins

    From the WaPo link:

    “It remains unclear whether the screening is worthwhile for younger men, a federal task force concluded yesterday.”

    And today I saw:

    “New research suggests that roughly one in five American men in their 40s has had a blood test to screen for prostate cancer within the last year.”

    http://www.reuters.com/article/healthNews/idUSCOL15189220080811

    Ok, so my back of the envelope math suggests that last year the US thus wasted at the low end some US$144,486,241 on this one test alone. At the high end, possibly US$825,635,600.

    Whoa. Even considering that some estimate the US spent about US$2,214,400,000,000 on health care in 2004 (Can that actually be right? Do we actually now spend more on health care than food?), that’s serious cash.

    I must be making a mistake, can it really be that much?

  • isisdave

    A lot of public-health medicine is based on statistics, but the sample size I care about is n=1.

    The fact is, PSA is a test of limited value because it is not very specific; i.e., a “high” number correlates with presence of cancer < 20% of the time. It is, though, fairly sensitive: known cancer causes a "high" PSA nearly 80% of the time. So here I am at 59, five years after my initial PSA came in at 7.0. Negative biopsy, and it's STILL 7.0. So either I haven't got cancer, or the biopsy missed it and it's not very aggressive. Sure wish I knew which, as I plan to live past 90. Better tests are available. The PCA-3 is supposed to be 97% specific, so it appeals to people in my situation. Not approved in the US but available at about $450. I just read that Austria started using it regularly this summer. Another group is using PCA-3 and five other DNA markers; it's supposed to be even better. And a big study of EPCA-2 is coming up. I think the focus ought to be on "which test to screen with at what age, and in the presence of what results from earlier in life".

  • http://drchip.wordpress.com/ retired urologist

    isisdave:

    I’m so sorry to hear that you’re in this stress-producing situation. My 86 year-old mother, as she was instructed to do, went faithfully for her annual mammograms. This year, they finally found something in the right breast. Ultrasonically-guided needle biopsy showed a well-differentiated non-invasive cancer. Simple mastectomy was recommended. Well, the bright old girl said, “I’d rather have a flat chest that one breast, and I’ll eliminate the chance of this ever happening again.” Mammogram and MRI of the left breast was normal. She talked the surgeon into bilateral mastectomy. Histologic exam confirmed the one known cancer in the right breast, and *three others* on the left. The surgery was far more threatening to her survival than the cancers, and *she should never have known about them anyway*. Had she done what the tests indicated were necessary, she would have retained 75% of her cancer load.

    If you haven’t done so, read the first comment in this thread, especially the links. Your comment “known cancer causes a “high” PSA nearly 80% of the time” has no clinical practicality: if you know you have cancer, you don’t need a PSA test, unless you plan some unproven program of following it along until it reaches the “interventional” level. You mention better and better blood tests: like my mother’s mammograms, sooner or later some test will confirm your prostate cancer, if you keep at it long enough. As the first thread comment confirms, a 59 (or 54) year-old man with a normal PSA has only 6% less chance of having prostate CA than one with a PSA of 4.1-10.

    There is *almost* no evidence that metastatic prostate CA patients have greater survival if their treatment includes removal of the primary (the prostate gland), rather than waiting and treating the metastatic symptoms. *And*, the younger men are more likely to have the aggressive, early-metastasizing cell lines, which are usually metastatic when diagnosed.

    I have to hope that you did *not* read the first comment, or that if you did, you have good reason to reject it. The stress to which you are subjecting yourself is *known* to decrease suvival (MI’s, etc), while the aggressive treatment of prostate CA is not known to increase survival.

    Sadly, you are in the position described by Eliezer Yudkowsky (I’ve substituted “ignorance” for the original “stupidity”): “The happiness of ignorance is closed to you.  You will never have it short of actual brain damage, and maybe not even then.  You should wonder, I think, whether the happiness of ignorance is optimal – if it is the most happiness that a human can aspire to – but it matters not.  That way is closed to you, if it was ever open.” And it was.