CaRDO: A Tool for Empowering Cancer Registries to Publish Population-Level Cancer Statistics Online.

Introduction: Population-based cancer registries are critical for monitoring cancer burden, informing policy, and guiding cancer control strategies. However, many registries face challenges in effectively communicating their data, due to limited resources and technical capacity. There is a growing need for accessible tools that support the visualization and dissemination of cancer statistics in engaging and interpretable formats. Methods: CaRDO (Cancer Registry Data Online) was developed by the Viertel Cancer Research Centre at Cancer Council Queensland as a free, secure, and user-friendly R package for creating interactive dashboards using population-level cancer data. Built on the R Shiny framework, CaRDO enables users with minimal programming experience to generate dashboards entirely offline. The tool incorporates standard epidemiological methods, including age-standardized rates, lifetime risk estimation, and segmented regression for trend analysis, while maintaining strong privacy safeguards. Results: CaRDO allows users to display cancer incidence and mortality data by sex, cancer type, year, age group, and measure (counts or rates), with visualizations of underlying temporal trends. All data processing occurs locally, and dashboards can be customized with plots that can be downloaded for use in reports or presentations. Example datasets and detailed guidance are provided to support implementation. The current version includes core dashboard elements, with flexibility for future expansion. Conclusions: CaRDO provides a timely and practical solution for enhancing the visibility and utility of cancer registry data. By removing financial and technical barriers, it supports under-resourced registries in fulfilling their essential role in cancer control through transparent, datadriven public health communication.