Portuguese National Cancer Registry: from local registries to high-quality nationwide real-world data

Abstract

Background Portugal’s population-based cancer registries have evolved from fragmented municipal initiatives, starting in 1976, to full national coverage by 2007, culminating in the legislative creation of the National Cancer Registry [Registo Oncológico Nacional (RON)] in 2017. Patients and methods This short communication describes RON’s structural evolution, data quality, research utility, and readiness for international reporting. Results Although regional registries captured 20 core epidemiological variables, RON introduced >30 new clinical variables aligned with European Network of Cancer Registries recommendations, refining tumor characterization and treatment details. Analysis of 2022 data reveals that core incidence variables are 100% complete, with microscopic verification (97.8%), death certificate only (<0.1%), and unknown basis of diagnosis (<0.1%) meeting international benchmarks. However, challenges persist: stage is missing in 40.4% of cases, ill-defined morphology or topography affects 3.5%, unrelated surgical codes affect 14.9%, and poor stage standardization is evidenced by 779 recorded options. Despite partial automations, manual data entry remains substantial, contributing to a 3-year publication lag. Nevertheless, RON has supported 56 national and international studies since 2018, with data now sufficient for consideration in international reports. Conclusions Portugal has achieved remarkable progress in establishing a comprehensive national cancer registry with robust core data quality and growing international recognition. Strategic investments in automated data integration, real-time validation, targeted training, and phased data release, building on existing European collaborations, will further strengthen RON as a timely, high-impact resource for real-world oncology research and policy.