Four decades of population-based cancer incidence trends in Costa Rica: Implications for cancer surveillance in Central America.

e22551 Background: Reliable population-based cancer incidence data are essential for guiding cancer control strategies and evaluating long-term epidemiologic transitions. In Central America (Guatemala, Honduras, El Salvador, Costa Rica, Nicaragua, and Panama), national cancer burden estimates are largely derived from modeled data, and continuous registry-based incidence trends remain scarce. Costa Rica is the only Central American country with sustained representation in the Cancer Incidence in Five Continents (CI5plus) database, providing a unique opportunity to examine long-term cancer incidence patterns in the region. Methods: We analyzed population-based cancer incidence data from the CI5plus database for Costa Rica from 1982 to 2016. Annual crude incidence rates per 100,000 person-years were calculated by sex for all cancers excluding non-melanoma skin cancer and for major cancer sites. Temporal trends were assessed using Joinpoint-ready annual rate tables, enabling estimation of annual percent change (APC) and evaluation of long-term trend patterns. Analyses were stratified by sex and cancer type. Results: Over the 35-year study period, overall cancer incidence in Costa Rica demonstrated heterogeneous trends by sex and cancer site, including periods of increase, stabilization, and divergence between men and women. Prostate, stomach, lung, colorectal, breast, cervical, and liver cancers accounted for the majority of cases. Notably, stomach cancer—historically one of the most common malignancies—showed a substantial and sustained long-term decline in incidence (APC approximately −3% to −4% annually), particularly among men, contrasting with increasing or plateauing trends observed for prostate and colorectal cancers. This pattern is consistent with a true epidemiologic transition related to long-term changes in infection prevalence and living conditions rather than screening-related effects. Costa Rica remained the only Central American country with continuous CI5plus-quality incidence data throughout the study period. Conclusions: Costa Rica provides the sole long-term, high-quality population-based cancer incidence trends in Central America spanning more than three decades. The observed site-specific patterns, including the pronounced decline in stomach cancer, underscore the value of sustained cancer surveillance for identifying epidemiologic transitions. The absence of comparable CI5plus registries in neighboring countries highlights an urgent need to invest in high-quality, population-based cancer registries across Central America to support evidence-based, equitable cancer control and global oncology research.