Widespread use of cancer screening tests has raised concerns about possible over-diagnosis and over-treatment of early-stage cancers that may pose little risk to the patient. Cutting back on such tests, however, may lead to failure to find cancers that could become more serious in time for treatment and avoidance of bad outcome. Recent research and commentary in the Journal of the American Medical Association discusses this dilemma in the context of prostate cancer. (JAMA Article) The US Preventive Services Task Force, after years of controversy, recommended against routine PSA screening for prostate cancer in 2012. It was believed that this would eliminate “unnecessary” treatment of likely benign early stage tumors. Of course, there are no reliable tests at this time that tell someone that their early stage tumor won’t very quickly turn aggressive. The authors found that following this recommendation change, rates of screening declined by 18%. As you would expect, the number of prostate cancer diagnoses also dropped dramatically, from 498 men per 100,000 in 2011 to 416 per 100,000 in 2012. Note that it is not likely that there were this many fewer cancers, this just reflects less diagnoses due to less testing. This might be fine if all those now-undiagnosed cancers were unlikely to ever turn dangerous, but that is just as obviously not going to be the case. In a few years time we will undoubtedly see a rise in later-stage prostate cancer diagnoses, and depending on the treatments available at the time, an increase in mortality. By not screening, we are almost certainly condemning a number of men to more serious cancer illness.
Here is the real underlying issue. We have clinical professionals in this country, most not in the business of providing patient care on a full-time basis, who are concerned about the cost and other harms of certain medical diagnostics and treatments. That is fine, but in our current fit of guideline fever, they turn these beliefs into recommendations or mandates for care. We should have learned by now that all too frequently subsequent research undermines these guidelines. Until we have much more refined tools for precision in diagnosis and treatment, we are better off leaving it up to individual physicians and patients to decide what they are comfortable with. And patients should be fully informed that not testing means there is a heightened risk that they could have a tumor that is not discovered. In my mind it is better for someone to know that they have a cancer, even if likely to never be a serious health risk, and then be able to decide what treatment option to choose, including watchful waiting, than to never have the chance to make that choice early on. Over-diagnosis and over-treatment can lead to harms, but none of us want to be the patient who wasn’t screened, whose early-stage prostate cancer wasn’t detected, whose cancer then quickly turned aggressive and was discovered too late to prevent metastasis and likely death.