The association between estrogen-progestin replacement therapy and the risk of breast cancer among post-menopausal women: A systematic review and meta-analysis.

Abstract

Postmenopausal women rely on hormone replacement therapy to manage menopausal symptoms. Few studies have assessed the consequences of estrogen progestin replacement therapy (EPRT), a formulation prescribed to postmenopausal women with an intact uterus. The aim of this thesis was to conduct a systematic review and meta-analysis assessing the association between breast cancer risk and EPRT use among postmenopausal women. Electronic databases, handsearching and advice from experts were used to locate studies. A fixed effects model was used to calculate the combined estimate and its standard error. Statistical tests for association and homogeneity were performed. The association between breast cancer risk and EPRT exposure was significant for both case control (OR = 1.38; 95% CI 1.23--1.56; chi2 = 48.30, p < 0.0001) and cohort studies (RR = 1.42; 95% CI 1.29--1.57; chi 2 = 27.95, p < 0.0001). Results indicate that postmenopausal women on EPRT have a higher breast cancer risk, particularly with long term use and testosterone derived formulations.