Geographic Disparities in Oral Cancer Survival From 10 Population-Based Cancer Registries in India.

Importance: India accounts for more than one-third of oral cancer (OC) cases globally. Cancer survival measures the effectiveness of the health care system's cancer control efforts and the proportion of people who survive during a specified time. Objective: To estimate the 5-year survival rates among patients with OC diagnosed in India and assess the association of survival with age, place of residence, histologic type, and clinical extent of OC. Design, Setting, and Participants: This retrospective cohort study evaluated survival of patients diagnosed with primary OC (International Classification of Diseases for Oncology, Third Revision, codes C01-C06) between January 1, 2012, and December 31, 2015, and followed up until June 30, 2021. Patients were included from 10 population-based cancer registries (PBCRs). Data were analyzed between March 15 and August 20, 2024. Exposures: Demographic factors (patient age, sex, and place of residence) and disease factors (clinical extent of disease and histologic type). Main Outcomes and Measures: The main outcome was 5-year age-standardized relative survival (ASRS) for OC among male and female patients. A multivariable Cox proportional hazards model estimated hazard ratio (HR) and 95% CI, adjusting for covariates. Results: Data from the 10 PBCRs encompassed 14 059 patients of all ages (median age, 55 [IQR, 45-65] years; 10 380 male [73.8%]) diagnosed with OC. The overall 5-year ASRS rate for OC was 37.2% (range, 20.9%-58.4%). The estimated ASRS rates at 5 years were 36.0% (range, 20.7%-59.3%) for male and 39.6% (range, 21.4%-54.8%) for female patients. Ahmedabad urban had the highest 5-year ASRS at 58.4% (95% CI, 56.3%-60.4%) for both sexes, while Manipur had the lowest rates at 20.9% (95% CI, 14.9%-27.6%). Survival rates differed significantly between rural areas (34.1%; 95% CI, 31.4%-36.9%) and urban areas (48.5%; 95% CI, 47.4%-49.7%). Pooled data from Kollam and Thiruvananthapuram revealed that individuals 65 years or older (HR, 1.76; 95% CI, 1.44-2.14) and those with distant metastasis (HR, 3.95; 95% CI, 2.78-5.60) had a significantly higher risk of death. Conclusions and Relevance: In this cohort study from India, significant survival disparities were observed among patients with OC based on demographic factors and clinical characteristics. Survival rates were lower in rural areas compared with urban regions, underscoring the inequalities in quality of care and services and emphasizing the need to improve OC survival rates in India.