That’s the question Dartmouth’s Dr. Gil Welch asks in a column on the CNN website.
He reflect on last week’s news about a test in development that might find a single cancer cell among a billion healthy ones – as so many news stories framed it.
“But it’s not that simple. The test could just as easily start a cancer epidemic.
Most assume there are no downsides to looking for things to be wrong. But the truth is that early diagnosis is a double-edged sword. While it has the potential to help some, it always has a hidden side-effect: overdiagnosis, the detection of abnormalities that are not destined to ever bother people in their lifetime.
Becoming a patient unnecessarily has real human costs. There’s the anxiety of being told you are somehow not healthy. There’s the problem that getting a diagnosis may affect your ability to get health insurance. There are the headaches of renewing prescriptions, scheduling appointments and keeping them. Finally, there are the physical harms of treatments that cannot help (because there is nothing to fix): drug side-effects, surgical complications and even death. Not to mention it can bankrupt you.
Americans don’t need more diagnoses, they need the right diagnoses.
I don’t know whether this test will help some patients. It might, but it will take years to figure that out.
But I do know that the test will lead more people to be told they have cancer (or that their cancer has returned). That will lead more people to receive cancer treatment. Because these new patients are bound to be less severely ill (if they are ill at all), they will appear to do better. Many will assume that their doing better is because of the new test and early treatment. So the test will be performed more often. And a lot of money will be made along the way.
Ironically, what this test might actually teach us is that it’s not that unusual for healthy people to have an occasional cancer cell in their blood.”
Coincidentally, a urologist’s editorial in this week’s Journal of the American Medical Association discusses a study on treatment for men’s urinary incontinence following prostate cancer surgery. And this leads him to reflect on overtreatment as well. Excerpt:
“In the era of prostate-specific antigen (PSA) screening, the overdiagnosis rate of clinically indolent prostate cancer (defined as a screen-detected cancer that would not present clinically during the patient’s lifetime) is estimated to vary between 23% and 42%. A patient with this type of low-risk cancer, therefore, is exposed to the adverse effects of aggressive interventions, such as surgery or radiation, with little or no benefit. Several publications have documented the feasibility and safety of active surveillance, which consists of PSA testing and serial prostate biopsies and delay of aggressive therapy until the patient meets prespecified pathologic or biochemical thresholds. It is time that patients with prostate cancer and their physicians consider this option more seriously.
Clearly, many factors discourage the increased use of active surveillance, including patients’, family members’, and clinicians’ preconceived notions about cancer in general and prostate cancer specifically and financial incentives that encourage the use of aggressive intervention in this disease. While these obstacles may be difficult to overcome, it is important that clinicians rethink existing treatment approaches if the goal is reducing the incidence of complications–such as urinary incontinence–associated with treatment of localized prostate cancer.”