Breast self-exams may not reduce cancer-related mortality

Routine breast self-exams may increase the number of biopsies performed for benign disease, according to an updated system review from the Cochrane Database.

Researchers from the Nordic Cochrane Center in Denmark searched the Cochrane Breast Cancer Group Specialized Register, the Cochrane Library and PubMed for randomized clinical trials on the efficacy of breast self-exams. The article is an update to the original review published in April 2003.

Researchers analyzed data from two large population-based trials from Russia and Shanghai that included 388,535 women. In both studies, breast self-examination was compared to no intervention. Differences in breast cancer mortality were not observed between the groups (RR=1.05; 95% CI, 0.90-1.24; 587 deaths).

In the study from Russia, more cancers were detected in the self-exam group compared with the control group (RR=1.24; 95% CI, 1.09-1.41). However, this was not the case in Shanghai (RR=0.97; 95% CI, 0.88-1.06).

Compared to the control groups, screening groups had nearly twice as many benign biopsies (1,856 vs. 3,406; RR=1.88; 95% CI, 1.77-1.99).

Researchers also reviewed a large population-based trial that combined clinical breast examination with breast self-examination. Due to poor compliance, no follow-up and no conclusions, the intervention was discontinued. – by Stacey L. Adams

Cochrane Database Syst Rev. 2008;doi:10.1002/14651858.CD003373.

This review has several important limitations: the studies are international and the home countries may not have the same access to technology as we have here in the United States, so that their ability to detect small tumors may not be the same. This review is based upon two large population based studies, one in China and one in Russia. In the Russian study in particular, there are serious methodologic concerns, including no clear accounting for all participants, no comparable baseline data for the groups, the use of workers rather than the general population for the participants, and the Cochrane group's use of only one branch of the study (the St. Petersburg arm). The Chinese trial also used women working in a factory for their participants. Both studies did not include women over age 66, although age is the strongest risk factor for breast cancer among women. Bearing in mind all of these limitations, there were still more biopsies in the BSE arm without improving breast cancer survival, though the authors admit that very little tumor specific data is available and overall survival data is likely unreliable. In the end, I do not think this review justifies recommending breast self exam, but I also do not think it should force providers to recommend against it either. I think it is unlikely that BSE is going to be a major force in early detection of breast cancers.

– Noelle LoConte, MD

Assistant Professor, University of Wisconsin