April 23, 2018
Cancer Screening: It\

Cancer Screening: It's Your Decision

by John Swartzberg, M.D.

Many people are perfectly happy to have their doctors tell them which cancer screen­ing tests (and other preventive services) to have and when. But others, knowing that experts are divided about the risk/benefit ratio of certain screening tests, would like their doctors to engage them in shared decision-making. Unfortunately, that often doesn’t happen.

Two articles in JAMA Internal Medicine focused on this lack of shared decision-making, specifically about mammograms. In one case, the 40-year-old author was told by her gynecologist to get a screening mammogram, with no discussion of the potential benefits and harms, even after the patient raised questions. When she researched the matter herself (being a health journalist, she was well equipped to do this), she decided not to have a mammogram because she felt that the risks of false alarms, overdiagnosis, and overtreatment outweighed the small chance that the test would save her life. She made an informed decision, though many other women looking at the same data would opt for screening. She also found a new doctor.

In the other article, an 83-year-old woman, following her doctor's orders, underwent a routine annual mammogram, which found some­thing abnormal. This caused confusion and anxiety for the patient until a biopsy determined it was a false alarm. After discussing these events and their implications with her daughters, the patient decided to forgo future mammograms. The article's author, a nurse practitioner who is a friend of the patient, concluded that the doctor should have reviewed the possible outcomes of screening with her friend before she had to face a biopsy and, had the results been positive, the likeli­hood of aggressive treatment for a cancer that might never kill her. "We owe it to our patients to give them a choice, to offer options, and to share the potential risks and harms of those options," she wrote.

For women in their forties as well as those over 75, the U.S. Preven­tive Services Task Force says there are insufficient data about routine mammography, so decisions should be "individualized"—that is, made on a case-by-case basis. That means having discussions with a health care provider about the pros and cons of screening, taking into consideration the patient's age, health, values, and preferences. Why doesn't this happen more often? As the accompanying commentary in the journal pointed out, shared decision-making is easy to propose, but challenging to implement. "How do clinicians decide which among the myriad clinical decisions they face each day warrant a shared decision-making approach?" Such discussions can be very time-consuming, researching and explaining the statistics to patients can be difficult, and some practitioners may simply not be good at it.

This is where "decision aids" can play a role. For instance, should you get a PSA test for prostate cancer? Which test should you have for colorectal cancer? At what age should you stop all cancer screenings? Decision aids are tools (websites, DVDs, workbooks, or pamphlets) produced by hospitals, universities, or medical organizations to sup­plement patient-clinician discussions about various types of screen­ing. Unbiased, nondirective, and presented in a readily understood format, they help you make informed decisions consistent with your values and preferences. One good online listing of such aids comes from the Ottawa Hospital Research Institute: Patient Decision Aids.

Ask your health care provider about such aids if you are uncertain about a screening test. They won't make the decision for you, but can be a good way to get the conversation going and put "shared" back into the decision-making process.