Racial and Ethnic Disparities in Lung Adenocarcinoma Survival: A Competing-Risk Model

Race/ethnicity-specific disparities in lung cancer survival have been investigated extensively. However, more studies concentrating on lung adenocarcinoma (ADC), especially those using a competing-risk model, are needed. We examined race/ethnicity-specific differences in lung ADC survival.

Patients with ADC diagnosed from 2004 to 2015 were identified from the Surveillance, Epidemiology, and End Results program. Race/ethnicity was categorized into 4 groups: non-Hispanic white (NHW), non-Hispanic black (NHB), non-Hispanic Asian/Pacific Islander (NHAPI), and Hispanic. Lung cancer-specific mortality (LCSM) and other cause-specific mortality (OCSM) were evaluated using a competing-risk model.

On multivariate analysis, NHB patients experienced slightly lower LCSM (subdistribution hazard ratio, 0.96; 95% confidence interval, 0.94-0.98) and higher OCSM (subdistribution hazard ratio, 1.16; 95% confidence interval, 1.11-1.22) compared with NHW patients in the stage IV group. No significant differences were found in LCSM and OCSM between the NHB and NHW patients with early-stage ADC (stage I or II). Both NHAPI and Hispanic patients experienced lower OCSM and LCSM compared with the NHW patients. Additionally, NHB patients with stage IV tumors had a greater mortality risk of cardiovascular disease and a lower risk of chronic obstructive pulmonary disease than NHW patients.

The source of racial/ethnic survival disparities that exist between NHB and NHW patients was mainly found in patients with stage IV ADC. Reducing the greater mortality rate of cardiovascular disease among NHB patients and chronic obstructive pulmonary disease among NHW patients would be conducive to narrowing the racial/ethnic gaps. Further research is warranted to determine additional influencing factors, especially among patients with stage IV ADC.