Preclinical safety data reports Natural S-equol has little effect on 2 reproductive hormones

"About 50 percent of Asians and 20 to 30 percent of North Americans and Europeans, who in general consume less soy than Asians, have the ability to produce equol. Studies in Japan have documented an association between milder menopausal symptoms in equol producers as compared to non-producers."

Soy won't reduce cholesterol after menopause: MedlinePlus

The Soy - Breast Cancer Controversy - Cancerwise | Cancer blog from M. D. Anderson Cancer Center

"These studies provide further information that regular dietary soy as part of a normal diet is probably safe and, in fact, may be beneficial for women with breast cancer. These studies, as well as others, create a growing body of evidence that the current advice that all soy foods should be removed from the diet of a woman diagnosed with breast cancer is probably untrue.
The role of non-dietary soy products such as soy supplements, powders or pills and the use of heavily processed soy items such as soy cheese, soy hot dogs or soy turkey remain unclear and should be avoided.
As the research to date is observational in nature, future randomized trials are needed to verify if a beneficial effect truly exists for the use of dietary soy."

Soy product and isoflavone intake and breast cancer risk defined by hormone receptor status. 2009; Cancer Science

"he association between soy food consumption and breast cancer risk has been inconsistent. A hospital-based case–control study was conducted to assess the relationship between soy food intake and breast cancer risk according to the estrogen receptor (ER) and/or progesterone receptor (PR) status of breast cancer in Chinese women .....The protective effects of soy did not seem to differ by ER and PR breast cancer status."