Abstract PR10: Factors associated with decreased survival in epithelial ovarian cancer patients from the southern United States
Authors: Stewart Sherri L. , Thompson Trevor D. , Moore Angela R. , Rim Sun Hee , Wike Jennifer M. 
Published: February 2019

Background: Ovarian cancer is the fifth leading cause of cancer death among women. While there are no effective prevention methods available for ovarian cancer, adherence to standard treatment guidelines, which have been in place for almost two decades, has been shown to increase survival. However, 5-year ovarian cancer survival remains lower than for many other cancers including breast, uterine, cervical, colorectal, and prostate cancers. The objective of this study was to determine factors associated with lower survival in patients with epithelial ovarian cancer.

Methods: Medical records from ovarian cancer patients in Georgia (GA) and South Carolina (SC) were examined and demographic, tumor, treatment, and vital status information was abstracted. These states were chosen in part for their racially diverse ovarian cancer patient population. The study sample was limited to malignant epithelial ovarian cancer cases. The vast majority of women in the sample were diagnosed between 2009 and 2012, to allow for the availability of more complete and accurate treatment and vital status information at the time of analysis. A Cox proportional hazards model was used to determine factors significantly associated with epithelial ovarian cancer survival at 3 years in this patient sample. Results are presented as hazard ratios (HR) and 95% confidence intervals (CI).

Results: A total of 1,457 women were included in the analysis; 48% were from GA and 52% were from SC. A total of 68% of women in our sample had Type II epithelial ovarian cancer (high-grade serous adenocarcinoma [aca]), and 32% had Type I epithelial ovarian cancer (low-grade serous aca, endometrioid aca, clear cell aca, mucinous aca, or low-grade aca, not otherwise specified [nos]). After adjusting for demographic, tumor, and treatment factors, we found a significant association with race in that black women were more likely to die from epithelial ovarian cancer than white women (HR=1.25, 95% CI 1.04-1.51). The presence of comorbidities was also associated with decreased survival (HR=1.28, 95% CI 1.03-1.60 for 1 condition and HR=1.86, 95% CI 1.50-2.31 for 2+ conditions compared to no comorbidity). Additionally, women diagnosed with advanced-stage disease (FIGO stages II,III or IV) had worse survival. Tumor histology also had an effect on survival, but the effect differed within the standard Type I and Type II epithelial groups. Some Type I tumors, specifically clear cell aca, mucinous aca, and low-grade aca, nos were significantly associated with decreased survival compared to Type II tumors (HR=1.93, 95% CI, 1.38-2.71); however, low-grade serous aca and endometrioid aca Type I tumors had better survival than type II tumors (HR=0.68, 95% CI 0.48-0. 96). Other factors associated with increased survival included being treated at an NCI-designated cancer center (HR=0.63, 95% CI 0.50-0.80), receiving ovarian cancer-specific cytoreductive/debulking surgery (HR=0.53, 95% CI 0.43-0.66), and chemotherapy (HR=0.55, 95% CI 0.44-0.70).

Discussion: Our data show that the standard epithelial Type I and Type II histologic characterization masks key differences in survival within these categories. Our findings suggest it may be more appropriate to further divide the Type I category in studies related to epithelial ovarian cancer survival, and that using a Type I subcategorization may result in improved study design and more accurate survival estimates. Our findings also reveal a significant racial disparity in epithelial ovarian cancer survival. The increased mortality among black women with ovarian cancer may be related to lack of access to quality care or other socioeconomic factors. Future studies exploring these factors would help determine the underlying reasons for lower survival. Programmatic efforts that ensure receipt of standard treatment may help increase survival among black women.

Citation Format: Sherri L. Stewart, Trevor D. Thompson, Angela R. Moore, Sun Hee Rim, Jennifer M. Wike. Factors associated with decreased survival in epithelial ovarian cancer patients from the southern United States [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr PR10.