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We should aggressively screen for cancers early… right?


How can the idea of early detection and screening for cancers even be a debate? What could possibly be the downside of catching cancers early, and treating them before they cause great harm, even death? Logic says if you can’t prevent a cancer in the first place, then diagnose it as early as you can, and get it out of you! Right?

The answer may surprise you.

Contrary to what most of us believe, overdiagnosis and overtreatment of many cancers is a considerable threat to the health and well being of many.

You have probably read or heard recently that expert groups are now recommending against much of the currently routine prostate cancer screening via PSA. The same experts also issued controversial guidelines in 2009 regarding breast cancer screening.

These actions have understandably confused the public and inflamed patients and advocates. And it doesn’t stop at breast and prostate cancers. Sober second thought about all cancer screening will become more and more common as we ask tough questions.

Prostate Cancer and PSA Screening: One Example

There is no doubt whatsoever that the PSA test detects prostate cancers. But the test is prone to false negatives (not detecting a cancer that is really there) and also very prone to false positives (alarming a patient to a possible prostate cancer that is not really there).

So what is the harm of some false positives? Better to be safe than sorry, right?

Not if the false positive leads to an action that is more harmful than the disease itself! Prostate biopsies are very unpleasant, and often result in lasting side effects. Treatments for prostate cancer can lead to many serious consequences – not the least of which is impotence and/or incontinence, and other conditions that can severely and negatively affect a man’s quality of life.

Yet we know that the majority of prostate cancers develop late in life, are very slow growing and will never otherwise impair the health of the man harboring the cancer. The vast majority of men will develop prostate cancer in their lifetime without them ever knowing it, and will die WITH prostate cancer, but not FROM prostate cancer. Detecting a prostate cancer in these men may seem like a prudent course of action, but if they don’t know it’s there, and they will never suffer a day from it, then what is the value of detecting it in the first place, especially if that leads to a course of action that does harm or creates more problems than it solves?

So, Why Can’t We Stop Ourselves?

Many argue persuasively that despite the PSA test’s failings, it is the best we have right now, so let’s continue to use it, but do so more wisely. Doctors and patients, they say, should enter into more fulsome dialogues and have more shared decision-making so that patients are much better informed of the benefits and risks, and decide on a case-by-case basis whether PSA testing is right each individual.

This all sounds logical but if we are to educate men in this way, this dialogue MUST happen long before a blood sample is ever drawn. In my view, once there is a positive PSA test on the table, all bets are off – in effect the genie is now out of the bottle and it won’t easily be put back in.

Why is it too late at that time to debate the pros and cons of further investigation and/or treatment, as opposed to just leaving the cancer alone?

Two simple words – “cancer” and “fear”. Despite great strides in treating and curing many cancers, the very word “cancer” still conjures up a fear like no other. The very thought, for most people, of knowing a cancer is growing inside you swamps out your ability to ignore it, even if all evidence says that it will do you no harm.

If a cardiologist tells you that you have a mild heart murmur, you likely will not quake in fear or demand heart valve surgery. You probably will easily ignore it as long as it remains asymptomatic.

But if an oncologist tells you that you have a cancer, your first thought is likely to be “Oh my God, I’m going to die” and the second is likely “How do we get rid of it?”

Ignoring it because it won’t do you harm is just not in most people’s psyche, even if it all evidence says that is what you ought to do…

And so, I would argue that if you can’t put the genie back in the bottle after a PSA test comes back positive, think twice before you uncork the bottle in the first place.

I have no doubt that every prostate cancer survivor who had a PSA test is 100% convinced that he is alive today because of that test. And in some cases, that is no doubt true. But I’m also sure that he never stops to ask whether he was “cured” of something totally unnecessarily because it was never going to harm him in the first place. And yet he risked much, and it may indeed have cost him much (in pain, suffering and reduced quality of life) despite the fact that there was no good medical reason.

And so, the fear of cancer, perhaps more than any other factor, may be driving screening and treatment decisions at the individual level, and no doubt policy decisions at the societal level. We are getting there, but until we can take the fear out of a cancer diagnosis, I think this genie of overdiagnosis and overtreatment will never be able to be put fully back into the bottle, and all the logic, facts, data and evidence to the contrary will not prevail.

And the people who are harmed by all these good intentions may perhaps become bigger victims than those with cancers that are, and indeed ought to be, just left alone.

Michael A. Wosnick is a retired cancer researcher who blogs at Cancer Research 101.  This guest post was adapted from Cancers: To Screen; Perchance to Treat? (June 6, 2010) and Screening for Prostate Cancer – PSA Testing or Not? (May 22, 2010).  Follow Michael on Twitter @MichaelWosnick

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5 comments

  1. John Lynch

    Well done, as usual, Michael. The problem, of course, is that all this shared decision-making requires that doctors spend more time with patients. The social imperative to contain costs, combined with the medical imperative to maintain physician incomes, is taking us in the exact opposite direction.

    This leaves patients ever more susceptible to mass media misrepresentations that rely on sensationalism to drive ratings and revenues. And the notion that the public is being deprived of something they need and deserve – and that leverages the innate fear you describe – is vastly more sensational than encouraging viewers to fear their treatments as much as their medical condition.

    Until we overcome this inherent lack of respect for the damage that all medical treatments can inflict despite their good intentions, I fear it will remain an uphill battle. it’s a battle that must continue to be waged, however, if we’re to ever rationalize a health care system that often causes more harm than good.

    Thanks for your valiant efforts in that regard.

    • Dr. Michael A. Wosnick

      Hi John,

      I don’t have much to say about your comments other than you always create opportunities for interesting debate and discussion. I do think that it is the exact environment you describe, however, that allows charlatans to emerge and be so popular. I think of the anti-vaccine mob and the harm they have done (in this case by NOT treating) or the Suzanne Somers ilk that are just whacko in what they want us to take.

      And I know you have read the piece that I myself did recently on Dr Oz being a quack (http://www.michaelwosnick.com/dr-oz-a-case-of-celebrity-run-amok/) . These popularizers of snake oil remedies don’t help the overall situation do they?

  2. Terry Sullivan

    Nice job MIchael. It is of course useful to distinguish mass screening from high risk groups who should be watching with a different level of intensity than average risk individuals. Interestingly today ASCO (the American Society of Clinical Oncology) released a PCO (provisional clinical opinion) on PSA testing recommending against routine PSA testing for average risk individuals.

    They suggest that in older men with a longer than 10 years of life expectancy (using routinely available risk calculators), that a deliberative exchange occur between men and their physicians  which might hold some benefit for better decision making. A useful additional couple of tools include a patient guide summarizing the risks and harms and supporting patient choice using a decision aid. These tools may help to overcome the 'popularity paradox' that surrounds contentious screening for prostate cancer in average risk men.

    • Dr. Michael A. Wosnick

      Hi Terry,

      I agree on the need to distinguish mass screening of well individual from those who have some identifiable risk. And I don’t think the PSA situation, as an example, ever said that no one ought to use PSA at any time. I did see the ASCO position on this and perhaps that is one reasonable way to saw this debate off – but I still think that it will lead to more people being screened than ought to be. And as I suggested, once a positive test is on the table, it is hard to just let it be at that time (for most people anyway).

      In the end, of course, what we need, as you well appreciate, is a better test than PSA and then this whole debate goes away anyway (for prostate cancer and PSA at least) . If we had a much more solid biomarker that truly identified prostate cancer from among the other PSA-altering conditions, and just as importantly, that identified aggressive (need to treat) prostate cancer as opposed to indolent ones, then we would have a much clearer path to make good policies and good recommendations.

  3. Ritika Goel

    Excellent piece addressing a really difficult issue. I’ve definitely also had pushback from patients on the recent change to cervical cancer guidelines with paps only being every 3 years. Some patients still want their annual pap ‘just to be safe’. Ofcourse much less issues with unnecessary testing and treatment with paps than PSAs, but similar concept.

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