Risk factors for glioblastoma in adults in Japan: an exploratory cohort study based on the Shizuoka Kokuho Database, the Shizuoka study

Purpose To elucidate the risk factors associated with the onset of glioblastoma (GBM) utilizing a comprehensive administrative claims database from a major governmental district in Japan. Methods Using the Shizuoka Kokuho Database (SKDB) for the period from April 2012 to September 2021, we conducted a retrospective analysis of 1,465,353 participants, identifying GBM cases using specific Japanese disease codes in conjunction with associated treatments. Risk factors were assessed using both univariable and multivariable Cox proportional hazards models. Results Within the cohort, 182 participants (0.012%) received a GBM diagnosis during the study period, resulting in an incidence rate of 2.1 per 100,000 person-years. The multivariable analysis revealed that older age, male sex, and peripheral vascular disease (PVD) significantly influenced the risk of GBM onset. No clear link was found between allergic conditions and GBM risk, in contrast to some previous research. Conclusion Employing a robust health insurance database, this study revealed significant associations between GBM and factors such as age, male sex, and PVD within the Japanese population. It provides key insights into GBM epidemiology and underscores the potential of health insurance databases for large-scale oncological research.