Abstract B113: Equal opportunity for all? Does race/ethnicity predict overall survival after aggressive surgical therapy for appendiceal carcinoma?

Abstract

Abstract Introduction: In select patients, appendiceal cancer with peritoneal surface involvement is managed aggressively with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). There is limited to no data on the management and outcomes of this advanced disease across diverse patient populations. Here we report the first large-scale study evaluating the influence of racial/ethnic differences in outcomes for patients with appendiceal cancer undergoing CRS/HIPEC. Methods: The National Cancer Database (NCDB) 2019 Participant User File was queried for adult patients 18-89 years old, diagnosed with appendiceal cancer that underwent CRS/HIPEC from 2006-2018. Patients were stratified by racial/ethnic groups: non-Hispanic White, non-Hispanic Black, Hispanic, and Other. Differences in sociodemographics, treatment course, tumor characteristics, and postoperative outcomes were determined using Χ2 and Kruskal-Wallis tests. Kaplan-Meier survival analysis and Log-rank tests were conducted to assess for differences in survival. Cox Regression was used to evaluate for predictors of overall survival. Results: In total 2,532 patients were identified, of which 2,098 (82.9%) identified as White, 186 (7.3%) as Black, 127 (5.0%) as Hispanic, and 121 (4.8%) as Other. There were statistically significant differences for all sociodemographic factors across groups, including patient age, sex, insurance payor, distance traveled, treatment facility type, geographic location, and median income. There was no difference in year of diagnosis or burden of comorbidities shared by racial/ethnic group. Days from diagnosis to surgery, tumor grade, surgical margins, hospital length of stay, and rates of readmission were similar between all groups. There was also no difference in 30-day or 90-day mortality with similar lengths of follow-up. However, overall survival was found to be significantly different between all groups (p=0.0029) with Black patients having the shortest median survival of 106.7 months compared to Hispanic patients of 145.9 months (p=0.0093). Median survival for White patients was higher at 136.3 months. On multivariate analysis, race/ethnicity was found to be an independent significant predictor of overall survival. Black and White patients compared to Hispanic patients have increased risk of death after CRS/HIPEC for appendiceal cancer (HR: 2.117 [1.306, 3.431], p=0.0023 and HR: 1.549 [1.007, 2.383], p=0.0463, respectively). Conclusions: Racial/ethnic disparities are strikingly apparent in sociodemographics and overall survival for patients with appendiceal cancer that undergo CRS/HIPEC. Despite having similar tumor and treatment characteristics, long-term survival diverged with Hispanic patients having a survival advantage, whereas non-Hispanic Black individuals had worse overall survival. Disparities in survivorship are not fully explained by social determinants of health, thus different underlying biologic and genomic influences that have yet to be determined may be at play in how this disease progresses. Citation Format: Devon C. Freudenberger, Luke Wolfe, Andrea N. Riner, Vignesh Vudatha, Kelly M. Herremans, Leopoldo J. Fernandez, Jose G. Trevino. Equal opportunity for all? Does race/ethnicity predict overall survival after aggressive surgical therapy for appendiceal carcinoma? [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr B113.