Rural patients with oral squamous cell carcinoma experience better prognosis and long-term survival.

Abstract

No studies have attempted to examine the role of geographic location on oral squamous cell carcinoma (OSCC) disease progression in the United States (US). The purpose of this study is to analyze rural-urban differences in prognosis and long-term survival in patients with OSCC. This retrospective cohort study utilizes the National Cancer Institute's (NCI) Surveillance, Epidemiology and End Results (SEER) database to examine primary OSCC diagnoses from 1990 to 2015 in the US. The primary predictor variable was patient Rural-Urban Continuum Code (RUCC) (rural vs. urban). The primary outcome variable consisted of overall survival time after initial diagnosis. Additional variables assessed include patient demographics, primary anatomical site of the cancer, histological diagnosis, stage/grade at time of diagnosis, and disease outcome. Descriptive statistics were calculated, and categorical variables were compared. Additional cumulative survival and univariate/multivariate analyses were performed. 46,678 cases of OSCC between 1990 and 2015 were identified. The rural subgroup was more likely to present at the time of diagnosis with a lower grade (p<0.001) and an earlier stage (p<0.001). Rural populations demonstrated superior overall survival (p<0.001), whereas urban populations were more likely to die as a result of their OSCC (p<0.001). After adjusting for all patient-specific factors, urban status still yielded a poorer disease prognosis. Living in rural areas is associated with better prognosis and long-term survival in patients with OSCC. Further studies are needed to better elucidate the mechanisms underlying these findings.