but past studies have shown poor compliance in taking it, and chemotherapy alone is insufficient to prevent endogenous estrogen release that can result in uterine or ovarian cancer (and these patients have a higher risk of the latter). For this reason, many gynecological surgeons have been removing both the uterus and ovaries at the same time. I'd also mention that even post-menopausal women do produce some circulating estrogens.
A large study out of Australia showed a 30% decrease in these subsequent cancers, but only if both the uterus and the ovaries are removed. There were some limitations to that study, but it remains the most persuasive to underscore the practice. It did ONLY show the benefit when both the uterus and the ovaries are removed--not ovaries alone. The reason for the latter seems unexpected, but it was a statistically valid finding.
I will also underscore that both the practice and the study were largely conducted on younger women, so whether that would be an appropriate recommendation for someone considerably older is questionable.