60 years of the IARC catalyzing capacity building for cancer prevention

Over the past 6 decades, the International Agency for Research on Cancer (IARC) has played a pivotal role in global cancer research capacity building. This study presents a comprehensive evaluation of IARC's capacity-building initiatives with a mixed-methods approach. We integrated qualitative and quantitative data from institutional records, outcome surveys, and a career-tracking study of postdoctoral fellows. IARC's capacity-building portfolio includes fellowships, digital-learning platforms, a summer school, and global networks such as the Global Initiative for Cancer Registry development, the Cancer Screening in 5 Continents project, and the Biobank and Cohort Building Network. Since 1966, approximately 30 000 professionals from most countries in the world have benefited from those initiatives, with a majority from low- and middle-income countries. Among tracked IARC postdoctoral fellows, since 1966, 76.5% remained in academia, and 18.7% had a role in public health policy. Qualitative findings highlight the impact of IARC training on individual careers, institutional capacity, and global cancer control strategies. IARC's sustained investment in capacity-building has strengthened the cancer research workforce and institutional infrastructures while reducing inequalities in low- and middle-income countries. These efforts have advanced leadership, equity, and evidence-based cancer prevention. As global health challenges evolve, continued support remains essential to achieving equitable cancer control worldwide.