High prevalence of secondary bladder cancer in men on radiotherapy for prostate cancer: evidence from a meta-analysis

Shankun Zhao,1,* Qiang Xie,2,* Redian Yang,1,* Jiamin Wang,1 Chaofeng Zhang,1 Lianmin Luo,1 Zhiguo Zhu,1 Yangzhou Liu,1 Ermao Li,1 Zhigang Zhao1 1Department of Urology and Andrology, Minimally Invasive Surgery Center, Guangdong Provincial Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China; 2Department of Reproduction, Southern Medical University Affiliate Dongguan People’s Hospital, Dongguan, China *These authors contributed equally to this work Objective: To assess whether radiotherapy (RT) for prostate cancer (PCa) was a risk factor for secondary bladder cancer (BLCa) through a meta-analysis.Materials and methods: The MEDLINE, Embase, and the Cochrane Library were systematically searched for all studies investigating the risk of BLCa in patients with RT. The association between RT and risk of BLCa was summarized using hazard ratio with a 95%CI. The protocol for this meta-analysis is available from PROSPERO (CRD42018090075).Results: Overall, 619,479 participants (age: 57–79 years) were included from 15 studies, 206,852 of whom were patients who received RT. Synthesis of results indicated that RT was significantly associated with an increased risk of BLCa compared with the risk in those who received radical prostatectomy or non-RT (overall HR=1.6, 95%CI: 1.33–1.92, P