Time Trends for Prostate Cancer Incidence from 2003 to 2013 in South Korea: An Age-Period-Cohort Analysis

Purpose Prostate cancer (PCa) incidence is affected by aging phenomenon and performance of screening test. In United States, PCa incidence is affected by period effect of U.S. Preventive Services Task Force (USPSTF) recommendation. However, no study has reported the effect of USPSTF recommendation or aging phenomenon on PCa incidence in South Korea. Thus, the objective of this study was to investigate effects of age, period, and birth cohort on PCa incidence using age-period-cohort analysis. Materials and Methods Annual report of cancer statistics between 2003 and 2013 from National Health Insurance Service (NHIS) in South Korea for the number of PCa patients and Korean Statistical Information Service (KOSIS) data between 2003 and 2013 from national statistics in South Korea for the number of Korean male population were used. Age-period-cohort models were used to investigate effects of age, period, and birth cohort on PCa incidence. Results Overall PCa incidence in South Korea was increased 8.8% in annual percentage (95% confidential interval, 6.5 to 11.2; p < 0.001). It showed an increasing pattern from 2003 to 2011 but a decreasing pattern from 2011 to 2013. Age increased the risk of PCa incidence. However, the speed of increase was slower with increasing age. PCa incidence was increased 1.4 times in 2008 compared to that in 2003 or 2013. Regarding cohort effect, the risk of PCa incidence started to increase from 1958 cohort. Conclusion PCa incidence was affected by period of specific year. There was a positive cohort effect on PCa incidence associated with age structural change.