State-wise forecasting of cancer incidence in India using a moderated exponential regression model incorporating healthcare system determinants

Background: Cancer incidence in India varies substantially across states and union territories, posing a significant and growing public health challenge. Accurate projections of future cancer burden are essential for effective health planning, resource allocation, and strengthening health systems. However, conventional forecasting approaches largely rely on historical incidence trends and often ignore regional differences in health-care capacity, which influence disease detection and reporting. Variations in infrastructure, oncology services, screening coverage, and health expenditure can significantly affect observed cancer incidence. This study proposed a moderated forecasting framework that integrates key state-level health-care indicators to generate more realistic and policy-relevant projections. Methods: A moderated exponential regression model was developed using state-wise cancer incidence data from the National Cancer Registry Programme (ICMR-NCRP) for 2019-2022. The model incorporated multiple health system moderators, including cancer hospitals, oncologist availability, screening coverage, CHC/PHC density, health infrastructure index, per-capita health expenditure, and hospital-bed availability. Three projection scenarios were constructed: short-term (2026) using health-care facility density, medium-term (2030) incorporating infrastructure and workforce variables, and long-term (2045) including all seven moderators. Results: The moderated models revealed substantial inter-state variation in projected cancer incidence. States with stronger health systems exhibited slower increases, whereas those with weaker infrastructure showed more rapid growth. Model fit and predictive accuracy improved significantly compared to conventional exponential models. Conclusions: Incorporating health-care system factors enhances the reliability of cancer incidence projections. The proposed framework offers a robust, evidence-based tool for policy planning and targeted health system strengthening in India.