Urologic Oncology: Seminars and Original Investigations 32 (2014) 51.e1–51.e7 Original article Risk of prostate and bladder cancers in patients with spinal cord injury: A population-based cohort study 1 Wen-Yuan Lee, M.D. a,b,c,2 , Li-Min Sun, M.D. d,2 , Cheng-Li Lin, MSc e,f , Ji-An Liang, M.D. b,c,g , Yen-Jung Chang, Ph.D e , Fung-Chang Sung, Ph.D f , Chia-Hung Kao, M.D. b,c,h, * a China Medical University Hospital Taipei Branch, Taipei, Taiwan b Graduate Institute of Clinical Medical Science, College of Medicine, China Medical University, Taichung, Taiwan c School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan d Department of Radiation Oncology, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan e Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan f Institute of Public Health, College of Public Health, China Medical University, Taichung, Taiwan g Department of Radiation Oncology, China Medical University Hospital, Taichung, Taiwan h Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan Received 7 May 2013; received in revised form 4 July 2013; accepted 31 July 2013 Abstract Objective: To evaluate the risk of prostate and bladder cancers in patients with spinal cord injury (SCI). Materials and methods: We used data obtained from the National Health Insurance system of Taiwan for this study. The SCI cohort contained 54,401 patients with SCI, and each patient was randomly frequency matched with 4 people from the general population (without SCI) based on age, sex, and index date. Incidence rates, SCI cohort to non-SCI cohort rate ratios, and hazard ratios were measured to evaluate the cancer risks. Results: Patients with SCI showed a significantly lower risk of developing prostate cancer compared with subjects without SCI (adjusted hazard ratio ¼ 0.73; 95% confidence interval ¼ 0.59, 0.90), after accounting for the competing risk of death. No significant difference in the risk of bladder cancer emerged between the SCI and control groups. Further analyses found a higher spinal level of SCI tended to predict a lower risk for prostate cancer. Conclusions: Patients with SCI incurred a lower risk for prostate cancer compared with people without SCI. The risk for bladder cancer did not differ between people with or without SCI. r 2014 Elsevier Inc. All rights reserved. Keywords: Spinal cord injury; Prostate cancer; Bladder cancer; Cohort study 1. Introduction Spinal cord injury (SCI) has a reported incidence in North America of 15 to 55 people per million [1–3]. The incidence in Taiwan is considerably higher at 150 people per million, according to nationwide data [4]. Advances in technology for the treatment and follow-up care of people with SCI have significantly improved the life expectancy of these patients to figures approaching that of the general population [5]. Thus, most patients with SCI are likely to encounter problems associated with aging, including cancer [6]. Prostate cancer is the fifth most common cancer among Taiwanese men. The age-adjusted incidence of prostate cancer among Taiwanese men in 2008 was 24.55 per 100,000 [7]. Earlier studies had reported a lower incidence of prostate cancer among patients with SCI compared with the general population [8–12]. By contrast, patients with SCI are known to be at an increased risk of bladder cancer compared with the general population, as shown in several studies [13–16]. One study showed that a higher spinal 1078-1439/$ – see front matter r 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.urolonc.2013.07.019 * Corresponding author. Tel.: þ886-42-205-2121, ext: 7412; fax: þ886-42-233-6174. E-mail address: d10040@mail.cmuh.org.tw (C.-H. Kao). 1 This work was supported by The Study Projects (DMR-100-076 and DMR-100-077) in our hospital; Taiwan Department of Health Clinical Trial and Research Center and for Excellence (DOH102-TD-B-111-004); Taiwan Department of Health Cancer Research Center for Excellence (DOH102-TD-C-111-005); and International Research-Intensive Centers of Excellence in Taiwan (I-RiCE) (NSC101-2911-I-002-303). 2 Wen-Yuan Lee and Li-Min Sun contributed equally to this work.