Disparate Molecular, Histopathology, and Clinical Factors in HNSCC Racial Groups

Abstract

Objective: Causes of differences in the higher incidence of and mortality from squamous head and neck cancer (HNSCC) in African American (AA) vs Caucasian Americans (CA) lack a consensus. We examined a comprehensive array of risk factors influencing health and disease in an access to care, racially diverse, primary HNSCC cohort. Method: The study cohort of 673 primary HNSCC comprised 391 CA and 282 AA. Risk variables included demographic, histopathology, and clinical/epidemiologic risk factors. Tumor DNA was interrogated for loss and gain of 113 genes with known involvement in HNSCC/cancer. Univariate analysis was followed by multivariate modeling with determination of c-index. Results: Of the 39 univariate differences in race as AA and CA, multivariate modeling (c-index = 0.81) retained 6 variables (pCDKN2A) and aneupoidy of SCYA3 than CA tumors. AA were more likely to be unmarried, to have radiation treatment, and be more likely to be current and past smokers. Insurance type as HAP (Health Alliance Plan), Blue Cross, Medicaid, Medicare, and other was a significant determinant of race. AA were more likely to have Medicaid and Medicare. Insurance status by stage and radiation by stage were not significant. Conclusion: Molecular modeling indicated significant differences between AA and CA for histopathology, patient factors, and tumor gene copy number alterations. Our data reiterate that for HNSCC, as in the case of other complex diseases, tumor genetics or biology is only one of many potential contributors to differences among racial groups.