Eligibility criteria for using menopausal hormone therapy in breast cancer survivors: a safety report based on a systematic review and meta-analysis

Abstract Importance Menopause hormone therapy (MHT) effectively alleviates menopausal symptoms. However, it is generally not recommended for breast cancer survivors, although the scientific evidence is scarce. Objective This study aimed to establish eligibility criteria for use of the MHT in breast cancer survivors based on a systematic review and meta-analysis of the literature. Evidence Review We conducted exhaustive literature searches until June 2022 in MEDLINE, The Cochrane Library, and EMBASE, using a tailored strategy with a combination of controlled vocabulary and search terms related to breast cancer survivors and MHT. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and assessed the risk of bias using the Cochrane and Risk of Bias in Non-randomized Studies - of Interventions tools. The quality of the evidence was graded according to grading quality of evidence and strength of recommendations criteria (A, high; B, moderate; C, low; and D, very low). We categorized MHT use into four levels: category 1 (no restrictions on use), category 2 (the benefits outweigh the risks), category 3 (the risks generally outweigh the benefits), and category 4 (MHT should not be used). Findings A total of 12 studies met the eligibility criteria. Analysis of the three randomized clinical trials using combined MHT or tibolone revealed no significant differences concerning tumor recurrence (relative risk [RR], 1.46; 95% CI, 0.99-2.24). A combined analysis of randomized clinical trials, prospective, and retrospective trials found no elevated risk of recurrence (RR, 0.85; 95% CI, 0.54-1.33) or death (RR, 0.91; 95% CI, 0.38-2.19). The eligibility criteria for patients with hormone receptor (HR)–positive tumors fell into categories 3B and 3C for combined MHT or estrogen alone and 4A for tibolone. For HR-negative tumors, the category was 2B and 2C. Conclusions and Relevance Our findings suggest that MHT could be a viable treatment alternative for breast cancer survivors experiencing menopausal symptoms, especially those with HR-negative tumors. Personalized management is recommended for each peri/postmenopausal woman facing a diminished quality of life because of menopause symptoms. Further randomized trials are needed before considering changes to current standards of care.