(HealthDay News) — Lifetime ovulatory years (LOY) are associated with the risk for epithelial ovarian cancer (EOC), according to a study published online Jan. 23 in the Journal of the National Cancer Institute.
Zhuxuan Fu, Ph.D., from the University of Pittsburgh Graduate School of Public Health, and colleagues examined the association between LOY and EOC among 26,204 controls and 21,267 cases from 25 studies.
The researchers found that LOY was associated with increased EOC risk (odds ratios, 1.014 to 1.044 per year increase). Apart from age at menarche, individual LOY components were also associated with EOC. For oral contraceptive use and pregnancies, the estimated model coefficient was 4.45 times and 12- to 15-fold greater than expected, respectively. There were associations observed for LOY with high-grade serous OC (HGSOC), low-grade serous OC (LGSOC), endometrioid, and clear cell histotypes (odds ratios, 1.054, 1.040, 1.065, and 1.098 per year increase, respectively); no association was seen for mucinous tumors. For HGSOC, estimated coefficients of LOY components were close to expected estimates, while they were larger than expected for LGSOC, endometrioid, and clear cell histotypes.
“Together, our findings suggest that ovulation suppression is not the sole mechanism whereby reproductive factors affect EOC overall and for non-HGSOC histotypes,” the authors write. “Identifying these mechanisms and understanding their individual and joint roles can provide deeper insight into disease etiology and potential risk-reducing approaches.”
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