Secondary Primary Prostate Cancer after Colorectal Cancer: A Nationwide Population-based Cohort Study in Korea

Colorectal cancer (CRC) and prostate cancer frequently occur in developed countries. There are several reports on the association between CRC and prostate cancer; however, the conclusions are inconsistent to investigate the association of the development of secondary primary prostate cancer among patients with prior primary CRC using a nationwide population-based dataset.

Patients registered in the Republic of Korea National Health Insurance System database who were diagnosed with CRC between 2007 and 2012 were followed-up until the end of 2015, and we investigated the new diagnosis secondary primary prostate cancer. We compared the incidence of prostate cancer in age-matched controls using the Cox proportional hazards models.

We analyzed a total of 85,455 first primary CRC survivors. During the follow-up period of 494,222 person-years, 2,005 patients (2.30%) developed secondary primary prostate cancer (incidence rate 4.06/1,000 person-years). The median duration of follow-up was 5.78 years. Compared with the general population, CRC patients had a significantly increased risk of secondary primary prostate cancer (HR = 2.30, 95% CI = 2.18-2.43; P < 0.001). Multivariate analysis (including age, sex, body mass index, hypertension, diabetes mellitus, dyslipidemia, and income) showed that age < 55 years (HR = 20.74, 95% CI = 11.81-36.41; P < 0.001) is a significant independent predictor of secondary primary prostate cancer development.

Men diagnosed with colorectal cancer are at an increased risk of secondary primary prostate cancer, particularly those aged < 55 years. The data suggests that colorectal cancer patients aged < 55 years require regular screening for prostate cancer.

Journal of cancer prevention. 2017 Dec 30 [Epub]

Hyun Soo Kim, Yoon Jin Choi, Dong Woo Shin, Kyung-Do Han, Hyuk Yoon, Cheol Min Shin, Young Soo Park, Nayoung Kim, Dong Ho Lee

Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea., Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul, Korea.