Abstract B096: Predictors of survival in black and white patients with malignant pleural mesothelioma

Abstract

Abstract Purpose: Malignant pleural mesothelioma (MPM) is a rare cancer, particularly among black patients, with a very poor prognosis. There is only one study directly examining prognostic factors of survival in white and black patients with MPM, based on SEER. The goal of this study was to use a large, nationwide cancer database to examine factors associated with survival in black and white patients with MPM. Methods: We used the National Cancer Database (NCDB) to identify black and white patients diagnosed with MPM from 2004-2013. Multivariable Cox proportional hazards models, stratified by race, were used to assess factors associated with overall survival (OS), using adjusted hazards ratios (HRadj) and 95% confidence intervals (CI). Covariates included age, gender, ethnicity, zip-code level education and income, insurance, Charlson-Deyo comorbidity score, histology, laterality, stage, receipt of treatment (surgery, chemotherapy, radiotherapy), hospital characteristics, and year of diagnosis. Results: There were 15,828 patients included; 15,109 white (95.5%) and 719 black (4.5%). After adjustment, black patients were significantly younger, living in areas characterized by lower educational attainment and income, more likely to be on Medicaid, to be from the South and to live closer to their hospital. Though not significant, black patients were less likely to receive surgery, radiotherapy, and chemotherapy than white patients. There were several differences in factors associated with OS for black and white patients. OS was significantly worse for older patients, but the association was stronger in black patients (HRadj [white]: 1.86, 95% CI: 1.56-2.21; HRadj [black]: 7.18, 95% CI: 3.39-15.20 for ≥80 vs. <50 years). A higher comorbidity score was associated with worse OS (HRadj [white]: 1.28, 95% CI: 1.19-1.37; HRadj [black]: 1.53, 95% CI: 1.12-2.09 for comorbidity score ≥2 vs.0). Among white patients, women had significantly better survival (HRadj: 0.81, 95% CI: 0.77-0.85), but not so among black patients (HRadj: 0.95, 95% CI: 0.74-1.21). Both groups derived benefit from radiotherapy (HRadj [white]: 0.84, 95% CI: 0.75-0.94; HRadj [black]: 0.41, 95% CI: 0.21-0.82) and chemotherapy (HRadj [white]: 0.67, 95% CI: 0.64-0.70; HRadj [black]: 0.75, 95% CI: 0.60-0.94); only white patients had significantly better OS with surgery (HRadj [white]: 0.78, 95% CI: 0.74-0.83; HRadj [black]: 1.06, 95% CI: 0.76-1.48). Conclusion: Prognostic factors associated with better OS vary by race. Some of these differences may reflect poorer access to quality healthcare among black patients and compounded socioeconomic effects. Differences in previous asbestos exposure with race could also play a role in the biology of the disease. Further work is needed to untangle these differences to determine best care practices and improve prognosis for all patients. Citation Format: Naomi Alpert, Maaike van Gerwen, Nisha Ohri, Raja Flores, Emanuela Taioli. Predictors of survival in black and white patients with malignant pleural mesothelioma [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B096.