A Cochrane review included 2 large population-based studies from Russia and Shanghai with a total of 388,535 women.There was no statistically significant difference in breast cancer mortality, relative risk 1.05 (95% confidence interval (CI) 0.90 to 1.24) (587 deaths in total). In Russia, more cancers were found in the breast self-examination group than in the control group (relative risk 1.24, 95% CI 1.09 to 1.41), while this was not the case in Shanghai (relative risk 0.97, 95% CI 0.88 to 1.06). Almost twice as many biopsies (3406) with benign results were performed in the screening group compared to the control group (1856), relative risk 1.88, 95% CI 1.77 to 1.99.
A systematic review including 6 RCTs in women aged 50–74 years invited for screening was abstracted in DARE. Breast cancer mortality was reduced by 28% among those screened. Early results from a randomised trial of breast self examination suggest no difference in cancer detection rate or characteristics of tumours detected between intervention and control groups, but significantly higher frequency of visits to specialists, referrals, and excision biopsies of benign lesions in the breast self examination group.
Comment: The quality of evidence is downgraded by study quality.