Racial disparities in histological subtype, stage, tumor grade and cancer-specific survival in lung cancer

Abstract

Background: Racial differences in lung cancer survival are well documented in the United States, but the fundamental causes are less clear. In this study we aimed to examine racial differences in lung cancer-specific survival (LCSS) and explore mediating factors.Methods: We used the Surveillance, Epidemiology and End Results database to obtain data pertaining to lung cancer patients from 2004 to 2017. Outcome was LCSS and covariates included nonclinical (age at diagnosis, gender, marital status, race) and clinical factors (tumor site, year of diagnosis, tumor grading, histological subtype, tumor-node-metastasis (TNM) stage, surgery status, chemotherapy status and radiation status). Kaplan-Meier methods served for comparative LCSS disparities among patients of different racial origins. Meanwhile, univariate and multivariate survival analyses were performed to determine racial disparities in LCSS.Results: Among 61,961 lung cancer patients, 75.70% were White, 12.80% were Black, 11.30% were Asian or Pacific Islander (API), and 0.20% were American Indian/Alaska Native (AIAN). In API patients, adenocarcinoma patients (54.5%) were more frequent than in White patients (43.2%), Black patients (44.1%) and American Indian/Alaska Native patients (41.2%). Black and API patients exhibited higher stage than White patients (P<0.01). However, our multivariate analysis identified API patients exhibited better LCSS than White patients (HR: 0.90, 95% CI: 0.88-0.93). Kaplan-Meier survival analysis confirmed that API patients exhibited best LCSS, especially in stage IV adenocarcinoma. Conclusions:The novel evidence obtained from this study enrich our knowledge of racial differences among lung cancer patients and suggest that race may be associated with LCSS.