Association of Race/Ethnicity, Stage, and Survival in Oral Cavity Squamous Cell Carcinoma: A SEER Study

OBJECTIVE: Survival differences in oral cancer between black and white patients have been reported, but the contributing factors, especially the role of stage, are incompletely understood. Furthermore, the outcomes for Hispanic and Asian patients have been scarcely examined. STUDY DESIGN: Retrospective, population-based national study. SETTING: Surveillance, Epidemiology, and End Results 18 Custom database (January 1, 2010, to December 31, 2014). SUBJECTS AND METHODS: In total, 7630 patients with primary squamous cell carcinoma in the oral cavity were classified as non-Hispanic white (white), non-Hispanic black (black), Hispanic, or Asian. Cox regression was used to obtain unadjusted and adjusted hazard ratios (HRs) of 5-year mortality for race/ethnicity with sequential adjustments for stage and other covariates. Logistic regression was used to examine the relationship between race/ethnicity and stage with adjusted odds ratios (aORs). RESULTS: The cohort consisted of 75.0% whites, 7.6% blacks, 9.1% Hispanics, and 8.3% Asians. Compared to whites, the unadjusted HR for all-cause mortality for blacks was 1.68 (P < .001), which attenuated to 1.15 (P = .039) after adjusting for stage and became insignificant after including insurance. The unadjusted HRs for all-cause mortality were not significant for Hispanics and Asians vs whites. Compared to whites, blacks and Hispanics were more likely to present at later stages (aORs of 2.63 and 1.42, P < .001, respectively). CONCLUSION: The greater mortality for blacks vs whites was largely attributable to the higher prevalence of later stages at presentation and being uninsured among blacks. There was no statistically significant difference in mortality for Hispanics vs whites or Asians vs whites.