Association between Oral Cancer and Smokeless Tobacco Use in Rural Indian Men: A Prospective Cohort Study.

Background: Smokeless tobacco (SLT) use, particularly gutka and khaini, is a significant public health concern in India, mainly in rural areas. This prospective cohort study aimed to investigate the association between SLT use and oral cancer incidence among rural Indian men. Methods: A cohort of 300 rural Indian men without a history of oral cancer was recruited and followed for five years. Baseline data on SLT use (type, frequency, and duration) and other risk factors were collected. Annual oral examinations and medical record reviews were conducted to identify incident cases of oral cancer. Incidence rates, relative risks, and hazard ratios (HR) were calculated to assess the association between SLT use and oral cancer. Results: Among the 300 participants, 185 (61.7%) were SLT users at baseline. During follow-up, 25 incident cases of oral cancer were diagnosed. The incidence rate of oral cancer was significantly higher among SLT users (24.3 per 1,000 person-years) compared to non-users (5.4 per 1,000 person-years). After adjusting for confounders, the HR for oral cancer associated with SLT use was 4.51 (95% CI: 2.03-9.98), indicating a significantly increased risk. A dose-response relationship was observed, with higher frequency and longer duration of SLT use associated with increased risk. Conclusions: This study provides strong evidence for a significant association between SLT use and increased risk of oral cancer among rural Indian men. The findings underscore the urgent need for targeted interventions to reduce SLT use and promote oral cancer awareness in this high-risk population.