Region-wise lung cancer burden, long-term trend & time-series forecasts in India: An analytical study by age, gender, & morphology

Background & objectives Lung cancer is the most diagnosed cancer and leading cause of cancer deaths. We assessed regional patterns in incidence, mortality, morphology, and mortality-to-incidence ratio across 57 populations, along with tobacco and alcohol use in India. We also estimated time-trends (average annual percent change: AAPC) by gender and age, and forecasted to 2030. Methods We used age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) (per 105 population) estimated AAPC via joinpoint regression and applied auto-regressive integrated moving average (ARIMA) model to forecast rates. Results Higher incidence of lung cancer among men was observed in the south, north and north-east regions of India. Highest ASIR was in Srinagar (39.5) and highest ASMR in Aizawl (27.1). Among women, highest rates were observed in the north-east, particularly in Aizawl (ASIR:33.7, ASMR:23.2). Tobacco use among women remains low outside the north-east, correlating with the patterns of lung cancer. Mortality to incidence ratio was low (<30%) except in a few populations. An increasing-trend in incidence was noted, with the highest AAPC in Thiruvananthapuram (women:6.7) and Dindigul (men:4.3). Adenocarcinoma has emerged as the dominant subtype over 25 yr, with higher prevalence among women, especially in Bengaluru (56.0%). Large-cell carcinoma increased notably in Delhi. By 2030, ASIRs are projected to range from 1.8 (Barshi) to 33.1 (Kollam) in men, and 1.9 (Barshi) to 8.1 (Bengaluru) in women. Interpretation & conclusion The burden of lung cancer in India shows regional disparities, with more adenocarcinoma, especially among women. Incidence is projected to rise, while low mortality to incidence ratio suggests underreported mortality, underscoring the need for better death reporting. Region-specific research beyond tobacco use is essential.