Overview
Cancer is the leading cause of death in Japan, creating an urgent demand for high-quality real-world evidence to improve patient care and support healthcare decisions. While clinical trials are essential for testing new drugs, they often exclude the diverse populations seen in daily practice, such as the elderly or those with multiple health conditions. Real-world data from insurance claims and hospital records can bridge this gap, but the quality of the research depends heavily on how much clinical detail these data sources actually capture.
In this study, researchers conducted a systematic review of 121 oncology studies published in Japan between 2020 and 2025 to evaluate the different types of data being used. They found that while insurance claims data was the most common source, it often lacked the critical clinical details—such as cancer stage, genetic mutations, or specific treatment responses—needed for robust analysis. In contrast, electronic health record (EHR) data provided much richer clinical insights but was used in only 6% of the studies reviewed, largely because these high-quality datasets are still emerging in the Japanese market.
Why this matters
This review highlights a major opportunity to modernize cancer research in Japan by shifting toward more detailed data sources. By identifying the strengths and limitations of current data, the study advocates for the increased use of EHR-derived datasets that capture the full complexity of a patient's journey. Leveraging these higher-quality data sources will enable more precise research and better decision-making, ultimately helping to bring safer and more effective treatments to Japanese patients more efficiently.