Abstract A06: Examination of racial/ethnic disparities in ovarian cancer survival: Multilevel analysis of 2001-2012 SEER data
Authors: Chen Chen , Tarasenko Yelena N. 
Published: May 2016

Background: While there has been a significant improvement in cancer-related survival over the past three decades, emerging studies suggest the degree of such improvement is not the same across all racial/ethnic groups. Ovarian cancer is the tenth most common cancer and the fifth leading cause of cancer-related deaths among women. Factors contributing to racial/ethnic disparities in ovarian cancer survival have been mainly examined at individual-level. Understanding contribution of contextual-level factors to racial/ethnic disparities in ovarian cancer survival is necessary for reducing and eliminating these disparities.

Objectives: The study aims to examine individual- and contextual- level factors contributing to racial/ethnic disparities in ovarian cancer-cause specific mortality.

Methods: Demographic, pathological, diagnosis, treatment, and survival information from women diagnosed with malignant ovarian cancer from 2001 to 2012 was extracted from the Surveillance, Epidemiology, and End Results (SEER) data of the National Cancer Institute (NCI). Indicators of county socioeconomic status (SES) were obtained from the United States Census 2000 and 2007-2011 data. The racial/ethnic disparities in 5-year ovarian cancer-cause specific mortality were analyzed using multilevel Cox-proportional hazards models.

Results: Adjusting for age at diagnosis, marital status, insurance status, tumor pathological characteristics, metro/nonmetro residence and county SES, compared to Non-Hispanic White (NHW) patients, Non-Hispanic Black (NHB) patients have 24% increased hazards of ovarian cancer death (95% CI: 1.18 – 1.30, p&lt;0.001). While not statistically significant, Hispanic patients have 2% (95%CI: 0.94 – 1.03) lower hazards than NHW patients. Both individual- and contextual-level factors contribute to these racial/ethnic disparities. Protective effect of being married was only significant in NHW patients (HR: 0.84, 95%CI: 0.82 – 0.87, p&lt;0.05) and NHB patients (HR: 0.82, 95%CI: 0.74 – 0.91, p&lt;0.05) but not in Hispanic patients (HR: 0.98, 95%CI: 0.90 – 1.07). Being insured was significantly associated with decreased risk of ovarian cancer death for NHW patients (HR: 0.79, 95%CI: 0.68 – 0.93, p&lt;0.05), but not for NHB patients (HR: 1.36, 95%CI: 0.99 – 1.88, p&gt;0.05) and Hispanic patients (HR: 1.03, 95%CI: 0.80 – 1.34). When diagnosed at advanced (vs. early) stage, the hazards of ovarian cancer death significantly increased by 4.65- fold in NHW patients (95%CI: 4.38 – 4.95, p&lt;0.05), 3.78-fold in NHB patients (95%CI: 3.24 – 4.41, p&lt;0.05), and 5.98 in Hispanic patients (95%CI: 5.05 – 7.09, p&lt;0.05). Receipt of surgery significantly decreased risk of ovarian cancer death; the effect sizes were similar across the racial/ethnic groups. Mortality difference by metro/nonmetro residence was significant for NHW patients (HR: 1.09 95%CI: 1.04 – 1.15, p&lt;0.05), but neither for NHB (HR: 1.05 95%CI: 0.89 – 1.25, p&gt;0.05) nor Hispanic (HR: 1.20 95%CI: 0.97 – 1.50, p&gt;0.05) patients. Living in counties with high employment rate or poverty level were each significantly associated with increased ovarian cancer-cause specific mortality in NHW patients, but not in NHB and Hispanic patients.

Conclusions: The contribution of individual- and contextual-level factors to ovarian cancer-cause specific mortality is varied by race/ethnicity. Future research on development of multilevel culturally tailored interventions is warranted to decrease racial/ethnic disparities in ovarian cancer-cause specific mortality.

Citation Format: Chen Chen, Yelena N. Tarasenko. Examination of racial/ethnic disparities in ovarian cancer survival: Multilevel analysis of 2001-2012 SEER data. [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 A06.