Vaginal estrogen therapy for treatment of menopausal genitourinary syndrome among breast cancer survivors: a systematic review and meta-analysis

Abstract Objective: Assess survival outcomes and risk of recurrence in vaginal estrogen therapy (VET) users with medical history of breast cancer. Data source: The search strategy was guided by standardized terms and keywords were identified from controlled vocabularies. Following databases were used for literature search: Pubmed, EMBASE, Cochrane, Scopus and Web of Science. Only studies published in the 21st century (2001–present) and written in English were included. Study selection: A total of 988 records were reviewed by two independent authors. After full-text analysis of 38 of them, 7 articles were included in the meta-analysis. Data collection: Data from eligible studies were extracted and tabulated based on predefined criteria: author, country, year, study type, sample size, type of intervention, use of aromatase inhibitors, duration of follow-up, and main outcomes. Results: 118.659 breast cancer survivors were analyzed, of whom 6.358 were treated with VET. The overall analysis showed no significant increase in the risk of recurrence (RR = 0.87, 95%CI: 0.67-1.11). VET users had a significant reduction in all-cause mortality (RR = 0.80, IC95%: 0.75–0,86). Conclusion: Vaginal estrogen therapy appears to be safe in the management of menopausal genitourinary syndrome in breast cancer survivors and it is related to significantly lower all-cause mortality. Prospective Register of Systematic Reviews (PROSPERO): CRD42024602047