Abstract B177: Association between ethnicity and ovarian cancer tumor characteristics in Asian Americans in California

Abstract Background: Ovarian cancer is often associated with poor survival given that most patients are diagnosed at advanced stages when treatment is less effective. The disease is also very heterogeneous, consisting of various histologic subtypes that each have distinct epidemiologic and pathologic profiles. Given that some studies have noted ethnic-specific disparities in ovarian cancer survival when the Asian American population is disaggregated and certain tumor characteristics are associated with more favorable outcomes, we examined the relationship between Asian ethnic subgroup and ovarian cancer disease presentation. Methods: We included a total of 31,230 non-Hispanic White and Asian/Pacific Islander ovarian cancer cases diagnosed between 1996 and 2020 from the California Cancer Registry. Multivariable logistic regression with odds ratios (ORs) and 95% confidence intervals (CIs) was used to examine the likelihood of being diagnosed with tumors of a certain stage, grade, and histologic subtype, for each Asian ethnic subgroup compared to non-Hispanic Whites. Demographic and socioeconomic factors were considered in the analyses. Results: Most, but not all, Asian ethnic subgroups were less likely to be diagnosed with advanced stage ovarian cancer and more likely to be diagnosed with clear cell ovarian cancer compared to non-Hispanic Whites. For South East Asians, the odds of having advanced stage tumors were 43% lower than non-Hispanic Whites (OR=0.57, 95% CI 0.41-0.79) and the odds of having clear cell tumors were almost 200% higher than non-Hispanic Whites (OR=2.97, 95% CI 1.92-4.61); only South Asians did not show lower odds of an advanced stage tumor diagnosis (OR=1.06, 95% CI 0.86-1.29) and higher odds of a clear cell tumor diagnosis (OR=0.93, 95% CI 0.63-1.37). Conclusion: There are clear differences in ovarian cancer disease presentation when each Asian ethnic subgroup is examined separately with South Asians constituting the only subgroup who did not show a lower likelihood of an advanced stage diagnosis and a higher likelihood of a clear cell diagnosis when compared to non-Hispanic Whites. Given that tumor stage and histologic subtype are considered important prognostic factors for ovarian cancer, identifying the underlying factors that may contribute to being diagnosed with certain tumor characteristics could provide clues to help us improve the survival of this highly fatal malignancy. Citation Format: Alice W. Lee, Jenny Chang, Sannia Siddiqui, Argyrios Ziogas, Robert E. Bristow. Association between ethnicity and ovarian cancer tumor characteristics in Asian Americans in California [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B177.