Trends in Incidence and Mortality of Oral Cancer in Sri Lanka 2005-2022: A Population-Based Temporal Analysis

INTRODUCTION: Lip and oral cavity cancer (LOCC) is a major global health burden, disproportionately affecting South and South-East Asia, including Sri Lanka, where tobacco use, betel quid chewing, and alcohol consumption remain key risk factors. Despite its preventable nature, incidence continues to rise, particularly among males and older adults. METHODS: Data from the Sri Lanka Cancer Registry were analysed for LOCC. Age-standardised incidence rates (ASIRs) were calculated for LOCC, while age-standardised mortality rates (ASMRs) were obtained from Vital Statistics for lip, oral cavity, and pharyngeal cancers (LOCP); corresponding ASIRs for LOCP were also derived for incidence-mortality comparisons. Temporal trends were assessed using Joinpoint regression (APC, AAPC). Mortality-to-incidence ratio (MIR) was used as a proxy for survival, and lifetime risk for 0 to 64 and 0 to 74 years was estimated to assess cumulative disease burden. RESULTS: A total of 42,526 LOCC cases were identified in Sri Lanka from 2005 to 2022, with a male: female ratio of 3.65:1. LOCC ASIR increased markedly from 9.8 to 26.1 per 100,000 in males and from 2.9 to 5.7 in females, representing 2.7-fold and 2.0-fold increases, respectively. Overall, LOCC showed a significant upward trend (AAPC 4.26%, 95% CI: 3.24-5.28; P < .001), with steeper increases in males (4.90%) than females (3.00%). The greatest rise was observed in the 0 to 34-year group (AAPC 6.03%), suggesting an increasing burden among younger age groups. MIR decreased steadily, with estimated survival improving from 54.7% to 74.0% in males and from 43.7% to 70.5% in females. CONCLUSION: LOCC incidence in Sri Lanka increased substantially, driven by oral cavity cancers, particularly among males and across younger and older age groups. Findings of this study provides evidence to strengthen oral cancer control policies and support stronger risk-factor control, risk-based screening, and earlier detection to reduce the oral cancer burden in Sri Lanka.