Thursday, November 19, 2009

What the research says on breast self-exams

The recommendations by the U.S. Preventive Services Task Force to forego breast self-exams (BSE) was based on research on the effectiveness of the exams. I found three studies, but the newest was in 2003. I continue to search for newer studies.

The studies below show no benefit, but have some flaws. In the Russian study, women did not follow through with the exams, so testing the BSEs effectiveness was compromised. And the Chinese study showed an equal number of cancers in the group that learned self-exams and the group that didn’t. This doesn’t address the issue of whether some of the cancers in the group that learned BSEs were found early enough to be treated.

The studies:

In a clinical tiral in St. Petersburg, Russia, 122,471 women between 40 and 64 were trained to perform BSE. One problem: many of these women did not actually practice self exams after they were taught how; after 5 years, only 55.8 percent of the women practiced BSE at least 5 times per year. After 9 years, the group that was taught self exams and the group that was not taught them had the same mortality rate from breast cancer, with no difference in the stage of breast cancers diagnosed. Self-exams did lead to a higher rate of biopsies for benign lumps. This was published in the journal Vopr Onkol in 1999.

In a randomized trial in Shanghai, China, 267,040 women ages 31-64 were taught BSE and were regularly reminded to practice the technique. Most women followed through during the study period and learned the BSE well. After about 10 years, the group that was taught self-exams and the group that was not taught them had the same breast cancer mortality rate, also with little evidence that BSEs led women to find their cancers earlier. The group that learned self-exams and the group that didn’t found the same number of cancers each year of the study. In addition, the number of cancers that had spread to the lymph nodes was similar in each group. Again, self-exams had more benign lumps than the control group did. This was published in the Journal of the National Cancer Institute in 2002.

A third study the Russian and the Chinese trials together and, likewise, found no benefits to breast self-exams. The review found twice as many biopsies with benign results in the groups taught self-exams compared to the groups who were not taught self-exams. This was published by the Cochrane Collaboration in 2003.

Sources:

Semiglazov VF, Moiseenko VM, Manikhas AG, et al. [Interim results of a prospective randomized study of self-examination for early detection of breast cancer (Russia/St.Petersburg/WHO)]. Vopr Onkol 1999;45:265-71.


Thomas DB, Gao DL, Ray RM, et al. Randomized trial of breast self-examination in Shanghai: Final Results. J Natl Cancer Inst 2002;94(19):1445-57.

Kosters JP and Gotszsche PC. Regular self-examination or clinical examination for early detection of breast cancer (Review). John Wiley & Sons Ltd. (for The Cochrane Collaboration) 2008.

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