Rauwolfia derivatives and breast cancer in hypertensive women.

Three groups of women were selected from a sample of death certificates that had been coded by the Office of Population Censuses and Surveys for all conditions mentioned on them: (1) all women with reference to both breast cancer and hypertension; (2) all women with reference to hypertension and other cancers; (3) a group of women with reference to hypertension without cancer, selected to match the breast-cancer patients with respect to five features. When the women with breast cancer were compared with both the women with other cancers and the women without cancer, there was a positive association between breast cancer and the use of rauwolfia derivatives, although neither the differences in the frequency nor duration observed were statistically significant. The association appeared to be strongest for use near the time of diagnosis of the cancer. This agrees with nearly all other data and would be expected if rauwolfia derivatives promoted the development of breast cancer from previously initiated cells.