Rethinking Local Cancer Overscreening in Japan: A Path toward Organized Screening.

Japan's cancer screening programs have expanded widely in recent decades, with local governments and workplaces offering screenings beyond national recommendations. Although this flexibility has improved access to screening, it has also contributed to overscreening and the practice of conducting tests beyond evidence-based age ranges, intervals, and methods. The underlying principles of organized screening, which emphasize evidence-based methods and quality assurance, have often been overshadowed by administrative and institutional momentum rather than by deliberate, evidence-based planning. In 2024, Miyazaki City initiated a comprehensive review of its cancer screening system under the new medical leadership. The process identified several deviations from national guidelines in target populations and screening methods, leading to a reform policy that discontinued non-evidence-based tests, such as the ABC method (a combination of serum pepsinogen and Helicobacter pylori antibody testing) for gastric cancer, breast ultrasound, and prostate-specific antigen testing. Although implementation is ongoing, this initiative demonstrates how municipalities can begin realigning screening practices with scientific standards. The Japanese case, exemplified by Miyazaki City's initiative, highlights the importance of local leadership and an organizational understanding of the principles of organized screening. Reforming overscreening requires sustained collaboration between policymakers, healthcare providers, and citizens to balance accessibility with evidence-based practices.