Research Results
Health-conscious women are different in many ways from other women, and experience negative health outcomes less frequently. It is not possible to tell which of their several health choices (including the practice of BSE) makes an important difference in prevention or early detection of an illness. The only way to find out about the effect of a particular intervention is to locate a large group of women and randomly assign half of them to receive the intervention, while making no changes in care in the other identical group of women. This type of randomized study cannot be done in regions where a practice like BSE is already common, because the health-conscious group of women who are most likely to use BSE have already decided to do it.
In a randomized study of 267,000 women in Shanghai, half were taught to practice BSE, and most of those women performed the procedure. The women in the BSE group found and reported more than twice as many benign breast conditions as women in the control group. However, the rate of breast cancer diagnosis was the same in both groups. Cancers found in the BSE group were not earlier in stage of development than cancers found in the control group, nor was there a difference in the death rates from breast cancer.
Another randomized study of 122,000 women was conducted in the USSR by the World Health Organization. As in the Chinese study, Russian women who learned BSE detected more benign breast problems and had more biopsies than women in the control group. Again, there was no difference in the rate of breast cancers detected, no difference in the size or stage of the cancers, and no difference in the proportion of cancers that had spread to the lymph nodes. Similarly, a 16-year study in the United Kingdom found no differences in the death rates from breast cancer between two regions (with 63,000 eligible women) that added a BSE training center to their usual health services and four comparison regions (with 127,000 eligible women) that had no BSE services.
