Assessment of Risk Factors Correlated with Age-Adjusted Mortality by Region for Prostate Cancer in Japan

Introduction Previous studies have suggested that smoking and drinking alcohol are prostate cancer risks. However, how regional unevenness of radiation oncologists/urologists in Japan or other risk factors correlate with age-adjusted mortality (ADM) of prostate cancer remain unknown. Methods In addition to those factors, we examined whether various other factors, such as the regional unevenness of radiotherapists/urologists, correlated with ADM for prostate cancer by region or prefecture. Statistical data were obtained from Annual Report of Hospital-Based Cancer Registries, Comprehensive Survey of Living Conditions and etc. We used the averages of ADM over the past 10 years in each prefecture to determine mortality rates. Results There was no correlation between the number of radiation oncologists/urologists per 100,000 and the averages of ADM over the past 10 years by prefecture in Japan. On the other hand, smoking rates and drinking per capita (liters) were correlated, respectively (P = 0.0002 and 0.0008). Conclusion The current study of statistics by prefecture in Japan also suggests that factors such as smoking and drinking alcohol are correlated with the risk of prostate cancer mortality. On the other hand, regional unevenness of radiation oncologists did not correlate. These results suggest that there is validity in this study design of analyzing factors of risk of prostate cancer fatality, even in macro statistics by region.