Evidence from non-randomized observational studies had not been consistent. Given such evidence, the U.S. Preventive Health Services Task Force currently does not recommend for or against the teaching of BSE.
To address this issue directly, David B. Thomas, M.D., Dr.P.H., of the Fred Hutchinson Cancer Research Center in Seattle, and his colleagues randomly assigned 266,064 female factory workers in Shanghai to either a BSE instruction group or a control group. Women in the BSE group were taught how to perform BSE and participated in reinforcement sessions 1 and 3 years later. The women also received regular reminders to practice BSE monthly and practiced BSE under medical supervision every 6 months for 5 years. The control group received no information on breast cancer screening.
After 10 to 11 years, there was no difference in breast cancer mortality between the BSE and control groups. There was also little evidence that cancers were detected at an earlier stage in the BSE group. However, women taught BSE found more benign breast lesions than women in the control group did during every year of the trial.
"In developing countries, where mammographic screening is not available, it would not seem to be a good use of the limited funds available for preventive services to promote practice of BSE," the authors write. For women with access to mammographic screening, the authors say that the results make clear that BSE is not a substitute for regular screening by mammography. They also point out that the implications of these results for women who do receive regular mammograms a
Contact: Linda Wang
Journal of the National Cancer Institute