Breast Self-Examinations: What You Need to Know
Q: I mentioned breast self-examinations to my doctor, and she said that current evidence does not support it – or even mammograms for my age group (I’m 48). Why wouldn’t doctors recommend anything that could help detect cancer early?
A Dr. Zachary Levine: A screening test is meant to detect cancer in its early stages before there are any symptoms, thereby maximizing the chances of a cure. Screening tests are available for breast, prostate, colorectal and cervical cancers, and researchers are always looking for effective screening tests for other cancers. But a good screening test is also one that is safe and that detects cancer early without many false positives (saying that cancer is there when it is not) or false negatives (saying that cancer is not there when it is).
False negatives are harmful because they falsely reassure, and false positives are harmful in that they lead to unnecessary anxiety and potentially to further unnecessary tests, which may incur risks of their own. In November 2011, the Canadian Task Force on Preventive Health Care (www.canadiantaskforce.ca) published updated recommendations on screening for breast cancer in average-risk women aged 40 to 74 years.
This was based on a review of the best evidence currently available and the number of false positive and negatives that resulted in these screenings. It is important to note that this is for women of average risk and not those who are at increased risk – such as those with first-degree family members (mothers, sisters) who have had breast cancer or women who are known to have the BRCA1 or BRCA2 genes. In general, for average-risk women, the task force feels that the evidence suggests that there may be more harm from breast self-examination and clinical breast examination by a physician than benefit in saving lives.
As noted, the harm comes in the form of unnecessary anxiety and testing. The decision whether to perform a screening test is an individual one, to be made in consultation with your doctor. A woman who is in her 40s and considered in the low-risk group may well decide that the relatively small reduction in mortality associated with mammography is worth the risk of potential unnecessary worry and testing. As for all screening tests, you and your doctor need to consider your individual risk for a disease, as well as the relative benefits and risks of performing the test, and come to a decision that you are comfortable with.