Lung Cancer Survival among Black and White Patients in an Equal Access Health System

Abstract

Racial disparities in lung cancer outcomes have been observed in the general population. However, it is unclear whether survival differences persist when patients have equal access to health care. Our objective was to determine if lung cancer survival differed among black and white patients in the U.S. Military Health System (MHS), an equal access health care system. The study subjects were 10,181 black and white patients identified through the Department of Defense's Automated Central Tumor Registry, who were 20 years old or more and diagnosed with lung cancer between 1990 and 2003. Racial differences in all-cause survival were examined using the Kaplan-Meier method and Cox proportional hazards regression models stratified by histology. For comparison, survival rates in the general population were calculated using Surveillance Epidemiology and End Results-9 data. Analyses included 9,154 white and 1,027 black patients: 1,834 small cell lung cancers, 3,876 adenocarcinomas, 2,741 squamous cell carcinomas, and 1,730 large cell carcinomas. Although more favorable crude survival was observed among black patients than white patients with small cell lung cancer (P = 0.04), survival was similar between the two groups after covariate adjustment. Racial differences in survival were nonsignificant for adenocarcinomas, squamous cell carcinomas, and large cell carcinomas. Survival rates appeared to be better in the MHS than in the general population. All-cause survival was similar among black and white lung cancer patients in the MHS. Providing equal access to health care may eliminate racial disparities in lung cancer survival while improving the outcome of all cases.