BACKGROUND: Medical professionals routinely teach women breast self-examination (BSE) as a screen for detecting breast cancer, yet there are conflicting recommendations regarding BSE from different professional organizations. One study has shown that only 7.6% of women with breast tumors who were practicing regular BSE actually detected the tumor by means of self-examination. Different studies have estimated the sensitivity of BSE as between 26% and 89% and the specificity between 66% and 81%. The US Preventive Services Task Force found insufficient evidence to recommend for or against teaching BSE. The purpose of this review was to evaluate the evidence relating to the effectiveness of BSE in preventing death of breast cancer to make recommendations for the Canadian Task Force on Preventive Health Care.
POPULATION STUDIED: The studies’ populations included women between ages 31 and 64 years in one study and from 40 to 69 years in the other studies. These women were from multiple areas of the world, including Shanghai, Russia, the United Kingdom, Canada, the United States, and Finland.
STUDY DESIGN AND VALIDITY: his is a systematic review of articles found using an electronic database search of abstracts and reports published from 1966 to October 2000. The author identified 2 randomized controlled trials, one quasi-randomized controlled trial, 2 large cohort studies, and several case-control studies that evaluated the effects of BSE on breast cancer outcomes. The 2 randomized-controlled trials and the quasi-randomized controlled trial were large studies enrolling more than 625,000 women with at least 5 years of follow-up and confirmation that women in the BSE group actually learned how to perform the maneuver. One of the cohort studies appeared to have a significant selection bias, rendering its results difficult to interpret. Since different designs were used in the review, the studies could not be combined using meta-analysis.
OUTCOMES MEASURED: The prevention of death resulting from breast cancer was viewed as the most important outcome. Other outcomes examined included the rate of benign biopsy results, the number of patient visits for breast complaints, the stage of cancer detected, and psychological benefits and harms.
RESULTS: Of the 8 studies included in this review, 7 studies, including the 2 randomized controlled trials and the quasi-randomized controlled trial, found no difference between groups taught BSE and the control groups with regard to rates of breast cancer diagnosis, breast cancer death, or in tumor stage or size. In the 2 randomized controlled trials and the quasi-randomized controlled trial, there were higher rates of benign biopsy results in the BSE groups, approximately 1 additional biopsy for every 200 women performing BSE. Women in the BSE groups also presented to the physician’s office more frequently for breast complaints.
This systematic review shows that BSE does not improve key health outcomes for women aged 40 to 70 years, and results in unnecessary biopsies, physician visits, and worry. This does not mean that women should ignore lumps that are detected incidentally, but that BSE teaching should be excluded from periodic health examination of women in this age group. Because all but one of the studies looked exclusively at women older than 40 years and younger than 70 years, no recommendations can be made for younger or older women. When asked by patients about BSE, the best approach is to relay the facts: (1) BSE has not been shown to improve breast cancer mortality; (2) BSE increases the number of physician visits for the evaluation of benign breast lesions; and (3) BSE increases the rate of benign biopsy results.