Cost of illness of the prostate cancer in Japan—a time-trend analysis and future projections

BACKGROUND The majority of patients with prostate cancer (International Classification of Diseases, 10th edition, code C61) are elderly. With Japan's rapidly society aging, both the prevalence and mortality of prostate cancer are expected to increase in the future. The objective of this study was to estimate and predict the cost of illness (COI) associated with prostate cancer in Japan. METHODS Using a COI method based on available data from government office statistics, we estimated the COI for 2002, 2005, 2008, and 2011. We then predicted the COI for 2014, 2017, and 2020 using fixed model estimation and variable model estimation. With fixed model estimation, only estimated future population was used as a variable. Variable model estimation considered the time trend of health-related indicators in the past 15 years. We derived the COI from the sum of direct and indirect costs (morbidity and mortality). RESULTS We found the predicted future COI of prostate cancer to be 354.7-378.3 billion yen in 2014, 370.8-421.0 billion yen in 2017, and 385.3-474.1 billion yen in 2020. Regardless of the estimation model, we found that COI would increase compared with the baseline year 2011 (307.3 billion yen). The direct costs for inpatient and outpatient treatment, laboratory tests, and drugs accounted for 60-75% of the COI of prostate cancer. CONCLUSIONS The results of this study suggest that the COI of prostate cancer in Japan has steadily increased and is expected to rise in the future. Direct costs comprised the largest proportion of the COI and are anticipated to continue expanding; this will result in increased burden on public funds in Japan, where a universal public insurance system operates. These trends differ from those with other forms of cancer.