Hormone therapy and risk of ovarian cancer in postmenopausal women: a systematic review and meta-analysis.
OBJECTIVE
Our objective was to perform a meta-analysis examining the risk of ovarian cancer with different types and regimens (continuous or sequential) of hormone therapy (HT).


METHODS
PubMed, Cochrane, and Embase databases were searched until December 2014 using the terms: HT, estrogen therapy (ET), ovarian cancer, postmenopausal, and menopausal. HT was considered unopposed ET, estrogen-progestin therapy (EPT), or ET+EPT (ET followed by EPT).


RESULTS
Of 180 studies identified, 12 were included in the meta-analysis. Of the 12 studies, 9 were cohort studies including 2,350,546 women and 7,549 cases of ovarian cancer, and 3 were case-control studies including a total of 1,347 cases and 2,052 controls. ET, EPT, and ET+EPT were associated with an increased risk of ovarian cancer: pooled hazard ratio (HR)/relative risk (RR) =1.37, 95% CI: 1.19 to 1.58, P<0.001; pooled HR/RR=1.27, 95% CI: 1.18 to 1.36, P<0.001; pooled HR/RR=1.55, 95% CI: 1.05 to 2.30, P=0.027, respectively. Continuous and sequential regimens were associated with an increased risk: pooled HR/RR=1.27, 95% CI: 1.04 to 1.54, P=0.018; pooled HR/RR=1.31, 95% CI: 1.08 to 1.58, P=0.006, respectively. HT was associated with an increased risk of serous ovarian cancer (pooled HR/RR=1.46, 95% CI=1.28-1.67, P<0.001), but not clear cell, endometrioid, or mucinous ovarian cancer.


CONCLUSIONS
Hormone therapy, regardless of type or regimen, is associated with an increased ovarian cancer risk.
Department of Obstetrics and Gynecology, No. 117 Center Military Hospital, Hangzhou, Zhejiang, P.R. China.
Li-feng
LF
Shi
Yan
Y
Wu
Cai-yun
CY
Li
D016022:Case-Control Studies; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D004967:Estrogens / Q000009:adverse effects; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D017698:Postmenopause; D011372:Progestins / Q000009:adverse effects; D016016:Proportional Hazards Models; D012306:Risk
D004967:Estrogens; D011372:Progestins