Lifetime ovulations and epithelial ovarian cancer risk and survival: A systematic review and meta-analysis

Objective. To assess the relationship between lifetime ovulatory years (LOY) and Epithelial ovarian cancer (EOC) risk and survival. Methods. A systematic review was performed in accordance with PRISMA guidelines. Relevant studies were identified from PubMed, MEDLINE, and Embase through December 31, 2021 combining the following search: [(ovulation or ovulation cycles or ovulatory age or ovulatory cycles) and (ovarian cancer or ovarian neoplasms) and (humans and female)]. Reference lists of identified articles were searched for additional studies. Studies were excluded from consideration if they were not a published, peer-review article; not in English; lacked data on effect sizes; had data induded in another publication; or were a review artide, cross-sectional study, or case report. Two independent investigators screened abstracts and full texts for eligibility, extracted study-level data, and assigned study quality. Disagreements between abstractors were discussed and resolved by consensus. Results. Thirty-one reports were included in the qualitative review of LOY and EOC risk, inclusive of 24 studies with sufficient data to be included in the meta-analysis. Women with the highest level of LOY had 2.26 times higher odds of EOC than women with the lowest level of LOY (95% CI 1.94-2.83). WY was associated with risk of serous (pooled OR 2.31, 95% CI 1.60-333) and endometrioid tumors (pooled OR 3.05, 95% CI 2.08-4.45) but not mutinous disease (pooled OR 1.52, 95% CI 0.87-2.64). There were only four studies examining the WYsurvival association, which precluded a quantitative assessment; however, three of the published studies reported worse outcome with greater LOY. Conclusion. LOY is a risk factor for specific EOC histotypes and may also influences EOC survival. Standard definitions of LOY, participant-level data, and larger sample size will enable more precise quantitation of the LOY-EOC association, which can inform EOC risk assessment models. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study aimed to assess the relationship between lifetime ovulatory years (LOY) and the risk and survival of epithelial ovarian cancer (EOC). The findings suggest that LOY is associated with an increased risk of EOC and specific histotypes of tumors. However, there is limited research on the association between LOY and survival, calling for further studies with larger sample sizes and more accurate data.