Abstract 2204: Evaluating ovarian cancer risk factors in the Mexican Teachers′ Cohort
Authors: Trabert Britton , Ramos Liliana Gómez Flores , Brochier Marion , Bandera Elisa V. , Doherty Jennifer A. , Gomez Scarlett L. , Kushi Lawrence H. , Mohar Alejandro , Lajous Martín 
Published: March 2024

Purpose: Ovarian cancer is the most lethal gynecologic cancer in North America, yet our understanding of ovarian cancer risk factors in Mexican women is limited. The aim of the present study was to prospectively evaluate associations between reproductive and lifestyle factors and incident ovarian cancer risk among Mexican women.

Methods: The Mexican Teachers′ Cohort (ESMaestras) is a large, prospective, population-based cohort of women (n=115,306) living in a culturally, geographically, and economically diverse 12-state area in Mexico. Reproductive and lifestyle factors were collected on baseline questionnaires administered between 2006-2008, with additional questionnaires collected from the cohort in 2011, and 2014. During follow-up, 187 incident ovarian cancer cases were identified, including 101 via self-report on 2011 and 2014 questionnaires, as well as an additional 85 through linkage with mortality databases, and 3 via other administrative- and cancer registry-based linkages (2 of 3 were also identified via the mortality database linkage). Of the self-reported incident cases, 5 have been validated via mortality databases and 4 via linkage with an administrative database; validation of the remaining self-reported cases is ongoing. Primary analyses examined associations between established ovarian cancer risk factors and incident ovarian cancer. Age-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression.

Results: Women in the Mexican Teachers′ Cohort that used hormonal contraceptives (HC), were parous, or had a tubal ligation experienced reduced ovarian cancer risks during follow-up (ever HC use vs. never HR 0.70 [95% CI 0.51-0.95], parous vs. nulliparous 0.48 [0.35-0.68], ever tubal ligation vs. never 0.87 [0.59-1.28]). Ovarian cancer risk was elevated among women with a positive family history of breast cancer (1.34 [0.76-2.36]). Women with a history of endometriosis were at increased ovarian cancer risk (3.43 [1.41-8.34]). Taller adult height (&gt;159 cm vs &lt;150 cm) was not associated with ovarian cancer risk among women in this cohort. Risk estimates were consistent and, in some instances, more pronounced (i.e., HC use and tubal ligation) when limited to incident ovarian cancer cases confirmed via linkage with mortality databases (n=90).

Conclusions: Ovarian cancer risk factors identified in the Mexican Teachers′ Cohort were generally consistent with associations reported in predominantly non-Hispanic white populations. More research is needed to better understand ovarian cancer etiology among populations under-represented in cancer research.

Citation Format: Britton Trabert, Liliana Gómez Flores Ramos, Marion Brochier, Elisa V. Bandera, Jennifer A. Doherty, Scarlett L. Gomez, Lawrence H. Kushi, Alejandro Mohar, Martín Lajous. Evaluating ovarian cancer risk factors in the Mexican Teachers′ Cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2204.