Reports on the expenditure of cancer treatments per patient using comprehensive data remain unavailable in Japan. This study aimed to use Japan's cancer registry data and health service utilization data for evaluating the disease-specific, per-patient costs of five major cancers-stomach, lung, colorectal, liver, and breast cancers. We used a database linking the 2017 data from a hospital-based cancer registry and the health service utilization data from the Diagnosis Procedure Combination survey. All patients who started their first treatment course at each hospital were included. The costs were calculated using the total volume of the health services provided and the unit fee information included in the data. We analyzed 304,698 patients. Lung cancer had the highest healthcare cost per-patient for the first year of diagnosis and the longest median hospitalization duration. Conversely, breast cancer showed the lowest cost and the shortest median hospitalization duration. However, in the first month after diagnosis, colorectal cancer showed the highest cost. Subsequently, the gaps between the costs of the five common cancers drastically diminished. The cancer type having the longest hospitalization duration had the highest overall healthcare resource utilization costs. This information is essential for care planning and research studies.
Keywords: Japan; healthcare costs; major cancers.