Effects of racial residential segregation on oral squamous cell carcinoma prognosis and survival

The objective of this study is to evaluate the impact of racial residential segregation on disease prognosis and overall survival in Black patients diagnosed with oral squamous cell carcinoma (OSCC), relative to White patients. This retrospective cohort study identified individuals diagnosed with OSCC between 2005 and 2015 using the Surveillance, Epidemiology and End Results Database. Patients were included with cancers diagnosed in the following locations: lip, tongue, gum, floor of mouth, palate, and other/unspecified. Tumors located at the base of tongue, tonsils, and oropharynx were excluded. The primary predictor variable was the degree of residential segregation. The primary outcome was overall survival. A Kaplan Meier survival analysis and univariate/multivariate analyses were performed to account for potential confounders of survival. A total of 35,769 patients met inclusion criteria. At the time of initial diagnosis, Black patients presented with OSCC of higher grades and more advanced stages ( p < 0.001 ). A greater number of Black subjects were dead by the time of last follow-up compared to White subjects ( p < 0.001 ). Across the entire spectrum of residential segregation, cumulative survival was worse among Black patients compared to Whites ( p < 0.001 ). Multivariate analysis identified highly segregated counties, advanced age, higher grade/advanced stage at time of diagnosis, lack of surgery, and no chemotherapy treatment as poor prognostic factors for survival among Black individuals. Racial residential segregation results in poorer long-term cancer survival among Black patients. Understanding the links between residential segregation and inequities in cancer outcomes will allow policymakers to better implement targeted, population-based interventions in treating various cancers.