Geography as an Independent Determinant and Immuno-Inflammatory Correlates of Long-Term Oral Cancer Survival: A...

India contributes approximately one-third of global oral cancer cases, with pronounced disparities in outcomes across geographic and socio-economic strata. While rural-urban survival differences have been documented, limited evidence exists regarding whether geographic residence independently predicts long-term survival.

We conducted a retrospective population-based cohort study using data from the Wardha Population-Based Cancer Registry, Maharashtra, for oral cancer cases (ICD-10 C00-C06) diagnosed between 2010 and 2022, with follow-up through December 2024. Overall survival was analysed using Kaplan-Meier methods and Cox proportional hazards regression. A mechanistic extension incorporated systemic immune-inflammatory biomarkers derived from pretreatment laboratory values, including neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, systemic inflammation response index, C-reactive protein/albumin ratio and CRP-albumin-lymphocyte index.

Among 12,847 registered cancers, 1683 (13.1%) were oral cancers; 66.2% were rural residents. Five-year survival was 42.1% for rural versus 56.3% for urban residents. Rural residence remained independently associated with mortality after adjustment for age, sex, education and clinical extent (HR 1.34, 95% CI 1.21-1.48). Rural patients demonstrated elevated inflammatory biomarkers and lower CRP-albumin-lymphocyte index. Sequential model adjustment demonstrated attenuation of the rural hazard ratio from 1.41 to 1.22.

Geographic residence independently predicts long-term oral cancer survival in this population-based cohort. Systemic immune-inflammatory biomarkers are associated with survival and partially account for rural-urban disparities.