menopause

The Clinical Problem
Because there is no universal definition of normal sexual function, what constitutes sexual difficulty is determined by a person’s subjective definition of unsatisfactory sexual well-being. The condition is usually described as unsatisfactory interest, arousal, orgasm, or other aspects of sexuality (e.g., sexual self-image), and the symptoms often coexist. The term “sexual dysfunction” is used when at least one of the symptoms is of substantial concern to the affected person. Sexual dysfunction negatively affects mental health, vitality, and social functioning and has an overall effect on quality of life that is of similar magnitude to that associated with chronic back pain or diabetes.

Importance: Approximately 55 million people in the US and approximately 1.1 billion people worldwide are postmenopausal women. To inform clinical practice about the health effects of menopausal hormone therapy, calcium plus vitamin D supplementation, and a low-fat dietary pattern, the Women's Health Initiative (WHI) enrolled 161 808 postmenopausal US women (N = 68 132 in the clinical trials) aged 50 to 79 years at baseline from 1993 to 1998, and followed them up for up to 20 years.

Observations: The WHI clinical trial results do not support hormone therapy with oral conjugated equine estrogens plus medroxyprogesterone acetate for postmenopausal women or conjugated equine estrogens alone for those with prior hysterectomy to prevent cardiovascular disease, dementia, or other chronic diseases. However, hormone therapy is effective for treating moderate to severe vasomotor and other menopausal symptoms. These benefits of hormone therapy in early menopause, combined with lower rates of adverse effects of hormone therapy in early compared with later menopause, support initiation of hormone therapy before age 60 years for women without contraindications to hormone therapy who have bothersome menopausal symptoms. The WHI results do not support routinely recommending calcium plus vitamin D supplementation for fracture prevention in all postmenopausal women. However, calcium and vitamin D are appropriate for women who do not meet national guidelines for recommended intakes of these nutrients through diet. A low-fat dietary pattern with increased fruit, vegetable, and grain consumption did not prevent the primary outcomes of breast or colorectal cancer but was associated with lower rates of the secondary outcome of breast cancer mortality during long-term follow-up.

Conclusions and relevance: For postmenopausal women, the WHI randomized clinical trials do not support menopausal hormone therapy to prevent cardiovascular disease or other chronic diseases. Menopausal hormone therapy is appropriate to treat bothersome vasomotor symptoms among women in early menopause, without contraindications, who are interested in taking hormone therapy. The WHI evidence does not support routine supplementation with calcium plus vitamin D for menopausal women to prevent fractures or a low-fat diet with increased fruits, vegetables, and grains to prevent breast or colorectal cancer. A potential role of a low-fat dietary pattern in reducing breast cancer mortality, a secondary outcome, warrants further study.

Importance: Menopause, due to loss of ovarian follicular activity without another pathological or physiological cause, typically occurs between the ages of 45 years and 56 years. During the menopausal transition, approximately 50% to 75% of women have hot flashes, night sweats, or both (vasomotor symptoms) and more than 50% have genitourinary symptoms (genitourinary syndrome of menopause [GSM]).

Observations: Vasomotor symptoms typically last more than 7 years and GSM is often chronic. Efficacious treatments for women with bothersome vasomotor symptoms or GSM symptoms include hormonal and nonhormonal options. Systemic estrogen alone or combined with a progestogen reduces the frequency of vasomotor symptoms by approximately 75%. Oral and transdermal estrogen have similar efficacy. Conjugated equine estrogens (CEE) with or without medroxyprogesterone acetate (MPA) were the only hormonal treatments for which clinical trials were designed to examine cardiovascular events, venous thromboembolism, and breast cancer risk. Compared with placebo, the increased risk of stroke and venous thromboembolism associated with CEE (with or without MPA) and breast cancer (with use of CEE plus MPA) is approximately 1 excess event/1000 person-years. Low-dose CEE plus bazedoxifene is not associated with increased risk of breast cancer (0.25%/year vs 0.23%/year with placebo). Bioidentical estrogens approved by the US Food and Drug Administration (with identical chemical structure to naturally produced estrogens, and often administered transdermally) also are available to treat vasomotor symptoms. For women who are not candidates for hormonal treatments, nonhormonal approaches such as citalopram, desvenlafaxine, escitalopram, gabapentin, paroxetine, and venlafaxine are available and are associated with a reduction in frequency of vasomotor symptoms by approximately 40% to 65%. Low-dose vaginal estrogen is associated with subjective improvement in GSM symptom severity by approximately 60% to 80%, with improvement in severity by 40% to 80% for vaginal prasterone, and with improvement in severity by 30% to 50% for oral ospemifene.

Conclusions and relevance: During the menopausal transition, approximately 50% to 75% of women have vasomotor symptoms and GSM symptoms. Hormonal therapy with estrogen is the first-line therapy for bothersome vasomotor symptoms and GSM symptoms, but nonhormonal medications (such as paroxetine and venlafaxine) also can be effective. Hormone therapy is not indicated for the prevention of cardiovascular disease.

Summary

Background

Published findings on breast cancer risk associated with different types of menopausal hormone therapy (MHT) are inconsistent, with limited information on long-term effects. We bring together the epidemiological evidence, published and unpublished, on these associations, and review the relevant randomised evidence.

Methods

Principal analyses used individual participant data from all eligible prospective studies that had sought information on the type and timing of MHT use; the main analyses are of individuals with complete information on this. Studies were identified by searching many formal and informal sources regularly from Jan 1, 1992, to Jan 1, 2018. Current users were included up to 5 years (mean 1·4 years) after last-reported MHT use. Logistic regression yielded adjusted risk ratios (RRs) comparing particular groups of MHT users versus never users.

Findings

During prospective follow-up, 108 647 postmenopausal women developed breast cancer at mean age 65 years (SD 7); 55 575 (51%) had used MHT. Among women with complete information, mean MHT duration was 10 years (SD 6) in current users and 7 years (SD 6) in past users, and mean age was 50 years (SD 5) at menopause and 50 years (SD 6) at starting MHT. Every MHT type, except vaginal oestrogens, was associated with excess breast cancer risks, which increased steadily with duration of use and were greater for oestrogen-progestagen than oestrogen-only preparations. Among current users, these excess risks were definite even during years 1–4 (oestrogen-progestagen RR 1·60, 95% CI 1·52–1·69; oestrogen-only RR 1·17, 1·10–1·26), and were twice as great during years 5–14 (oestrogen-progestagen RR 2·08, 2·02–2·15; oestrogen-only RR 1·33, 1·28–1·37). The oestrogen-progestagen risks during years 5–14 were greater with daily than with less frequent progestagen use (RR 2·30, 2·21–2·40 vs 1·93, 1·84–2·01; heterogeneity p<0·0001). For a given preparation, the RRs during years 5–14 of current use were much greater for oestrogen-receptor-positive tumours than for oestrogen-receptor-negative tumours, were similar for women starting MHT at ages 40–44, 45–49, 50–54, and 55–59 years, and were attenuated by starting after age 60 years or by adiposity (with little risk from oestrogen-only MHT in women who were obese). After ceasing MHT, some excess risk persisted for more than 10 years; its magnitude depended on the duration of previous use, with little excess following less than 1 year of MHT use.

Interpretation

If these associations are largely causal, then for women of average weight in developed countries, 5 years of MHT, starting at age 50 years, would increase breast cancer incidence at ages 50–69 years by about one in every 50 users of oestrogen plus daily progestagen preparations; one in every 70 users of oestrogen plus intermittent progestagen preparations; and one in every 200 users of oestrogen-only preparations. The corresponding excesses from 10 years of MHT would be about twice as great.

Funding

Cancer Research UK and the Medical Research Council.