Abstract PR05: Dietary quality and ovarian cancer risk in African American women
Authors: Qin Bo , Moorman Patricia G. , Alberg Anthony J. , Barnholtz-Sloan Jill S. , Bondy Melissa , Cote Michele L. , Funkhouser Ellen , Peters Edward S. , Schwartz Ann G. , Terry Paul , Schildkraut Joellen M. , Bandera Elisa V. 
Published: May 2016

Background: Ovarian cancer is the fifth leading cause of cancer death among women in the US. Considering the poor survival rates, identifying modifiable lifestyle factors including dietary interventions for ovarian cancer is needed. Compared to single foods or nutrients, examining dietary exposures as dietary patterns may allow us to accommodate the multidimensional aspects of diet and to better capture the role of diet in ovarian cancer carcinogenesis. Healthy Eating Index (HEI) is a measure of dietary quality to assess adherence to the Dietary Guidelines for Americans. Compared to HEI-2005 edition, HEI-2010 has an increased emphasis on dietary quality and reflects the most recent dietary guidelines. Alternate Healthy Eating Index-2010 (AHEI-2010), grounded in a different eating guide, the Healthy Eating Pyramid, was based on dietary predictors of chronic diseases. To our knowledge, this is the first study to evaluate the impact of dietary quality on ovarian cancer risk in African-American women.

Objective: We aimed to evaluate three index-based dietary patterns–HEI-2005, HEI-2010, AHEI-2010–in relation to ovarian cancer risk in African-American women.

Methods: Analyses were conducted among 415 cases of ovarian cancer and 629 controls using data from the African American Cancer Epidemiology Study (AACES). AACES is an ongoing population-based case-control study of ovarian cancer in African-American women in 11 sites in the US. Cases were identified through rapid case ascertainment and age- and site-matched controls were identified by random-digit-dialing. Information on risk factors related to ovarian cancer was collected by computer-assisted telephone interview. Dietary information 1 year before diagnosis (cases) or interview (controls) was obtained using a Block food frequency questionnaire (FFQ). AACES FFQ data were linked to the MyPyramid Equivalents Database 2.0 or based on published descriptions to generate equivalent intake for food groups under HEIs and AHEI-2010. Both HEIs includes 12 components, with total scores ranging from 0 to 100. AHEI-2010 includes 10 components with overall scores from 0 to 110. Higher scores indicate better adherence to a healthy diet. We used multivariate unconditional logistic regression models to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusted for potential socio-demographic and lifestyle risk factors.

Results: Only higher AHEI-2010 scores were associated with lower risk of ovarian cancer among all African-American women [OR comparing the highest quartile (Q4) vs. lowest (Q1) =0.66, 95% CI 0.45-0.98, p-trend =0.05]. The relationships between HEIs or AHEI and ovarian cancer risk were modified by menopausal status. Among post-menopausal women, we found lower risk of ovarian cancer with higher adherence of HEI-2010 (OR Q4 vs. Q1 =0.57, 95% CI 0.36-0.92, p-trend =0.03) and AHEI-2010 (OR Q4 vs. Q1 =0.49, 95% CI 0.31-0.78, p-trend =0.01). We observed no associations among pre-menopausal women. HEI-2005 was not associated with ovarian cancer risk among all or by menopausal status. Analyses evaluating individual score components with ovarian cancer risk suggested that in our sample of African-American women the benefits of HEI-2010 mainly come from higher intake of total vegetables, greens and beans, seafood and plant proteins and lower intake of empty calories (i.e., calories from solid fats, alcohol and added sugars). Consistently, the associations with AHEI-2010 were mainly driven by higher vegetable intake and lower intake of sugar-sweetened beverages and fruit juice.

Conclusion: Our findings suggest, for the first time, that a healthy diet is associated with lower risk of ovarian cancer in African Americans. Adherence to the current Dietary Guidelines for Americans may reduce ovarian cancer risk among post-menopausal African-American women.

This abstract is also presented as Poster A67.

Citation Format: Bo Qin, Patricia G. Moorman, Anthony J. Alberg, Jill S. Barnholtz-Sloan, Melissa Bondy, Michele L. Cote, Ellen Funkhouser, Edward S. Peters, Ann G. Schwartz, Paul Terry, Joellen M. Schildkraut, Elisa V. Bandera. Dietary quality and ovarian cancer risk in African American women. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr PR05.