OBG Management: Do your data give support to the timing hypothesis?
Dr. Manson: Yes, our findings do support a timing hypothesis that was particularly pronounced for women who underwent BSO. It was the women who had early surgical menopause (before age 45) and those who started the estrogen therapy within 10 years of having their ovaries removed who had the greatest reduction in all-cause mortality and the most favorable benefit-risk profile from hormone therapy. So, the results do lend support to the timing hypothesis.
By contrast, women who had BSO at hysterectomy and began hormone therapy at age 70 or older had net adverse effects from hormone therapy. They posted a 40% increase in the global index—which is a summary measure of adverse effects on cardiovascular disease, cancer, and other major health outcomes. So, the women with BSO who were randomized in the trial at age 70 and older, had unfavorable results from estrogen therapy and an increase in the global index, in contrast to the women who were below age 60 or within 10 years of menopause.
OBG Management: Given your study findings, in which women would you recommend estrogen therapy? And are there groups of women in which you would advise avoiding estrogen therapy?
Dr. Manson: Current guidelines6,7 recommend estrogen therapy for women who have early menopause, particularly an early surgical menopause and BSO prior to the average age at natural menopause. Unless the woman has contraindications to estrogen therapy, the recommendations are to treat with estrogen until the average age of menopause—until about age 50 to 51.
Our study findings provide reassurance that, if a woman continues to have indications for estrogen (vasomotor symptoms, or other indications for estrogen therapy), there is relative safety of continuing estrogen-alone therapy through her 50s, until age 60. For example, a woman who, after the average age of menopause continues to have vasomotor symptoms, or if she has bone health problems, our study would suggest that estrogen therapy would continue to have a favorable benefit-risk profile until at least the age of 60. Decisions would have to be individualized, especially after age 60, with shared decision-making particularly important for those decisions. (Some women, depending on their risk profile, may continue to be candidates for estrogen therapy past age 60.)
So, this study provides reassurance regarding use of estrogen therapy for women in their 50s if they have had BSO. Actually, the women who had conserved ovaries also had relative safety with estrogen therapy until age 60. They just didn’t show the significant benefits for all-cause mortality. Overall, their pattern of health-related benefits and risks was neutral. Thus, if vasomotor symptom management, quality of life benefits, or bone health effects are sought, taking hormone therapy is a quite reasonable choice for these women.
By contrast, women who have had a BSO and are age 70 or older should really avoid initiating estrogen therapy because it would follow a prolonged period of estrogen deficiency, or very low estrogen levels, and these women appeared to have a net adverse effect from initiating hormone therapy (with increases in the global index found).
Continue to: OBG Management: Did taking estrogen therapy prior to trial enrollment make a difference when it came to study outcomes?