Background:
The Global Initiative for Cancer Registry Development (GICR), coordinated by the International Agency for Research on Cancer (IARC), was established to strengthen population-based cancer registries (PBCR) worldwide, particularly in low- and middle-income countries. Among the objectives are to build and increase capacity to collect local cancer data, synthesize information, and disseminate results to support targeted actions addressing the increasing cancer burden. In Brazil, the National Cancer Institute (INCA) has been a key partner of the GICR, working closely with IARC to improve the quality and performance of population-based cancer registries.
 
Objectives:
To describe and evaluate the impact of coordinated capacity-building activities and site visits, performed by IARC/GICR and INCA on data quality and performance of Brazilian PBCR, and to highlight key lessons for strengthening cancer registration, during 2021-2024.
 
Methods:
We summarised activities conducted between 2021 and 2024, including training initiatives, as a data quality webinar (2021) with pre- and post-assessment reports, and on-site technical visits. Training activities focused on data quality, using standardized IARC tools and methodologies. Follow-up monitoring assessed changes in key indicators, including the proportion of cases registered from death certificates only (DCO%) and the proportion of microscopically verified cases (MV%). Qualitative information from site visits and meetings with local health authorities were also described to contextualize operational and sustainability challenges.
 
Results:
The coordinated training and follow-up strategy resulted in measurable improvements in data quality across participating PBCR. Among registries actively followed after the data quality webinars, most showed reductions in DCO% and stabilization or improvement in MV%. These improvements translated into an increase of Brazilian PBCR included in Cancer Incidence in Five Continents (CI5), with nine registries meeting publication standards in CI5 Volume XII compared to six in Volume XI. On the other hand, the impact of on-site technical visits was more limited. Although these visits included formal meetings with local health authorities aiming to raise awareness of the importance of PBCR, they did not consistently result in effective structural or operational changes. In many settings, recommendations related to staffing reinforcement, institutionalization of registries, legal access to data sources, and sustainable funding were only partially implemented or not implemented at all. Persistent challenges such as high staff turnover, dependence on short-term political commitment, and the absence of formal regulatory frameworks continued to limit PBCR activities after the visits.
 
Conclusions/Implications:
This experience demonstrates that sustained and structured collaboration between national cancer control institutions and IARC/GICR can contribute to improvements in PBCR. However, the limited impact of site visits indicates that engagement with local authorities is not always translated into long-term actions. Without stable funding, strong local institutional commitment, and clear legal frameworks, technical gains remain fragile. Strengthening cancer surveillance requires coordinated national action across technical, political, and regulatory levels to increase awareness regarding the importance of PBCR, ensure sustainability and the continuity of PBCR contribution to national cancer control policies.