Association Between Radiotherapy For Prostate Cancer And Risk Of Secondary Bladder Cancer:Meta-analysis

Purpose:To access 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.Meta-analyses were performed by Stata 13.0.The association between RT and risk of BLCa was summarized using hazard ratio(HR)with a 95%confidence interval(CI).Subgroup and sensitivity analyses were conducted to detect potential bias.Results:Overall,619479 participants(age:57-79 years)were included from 16 studies(15 articles),206852 of whom were patients received RT.Synthesis of results indicated that RT was significantly associated with an increased risk of BLCa compared with the risk in those received radical prostatectomy or non-RT(overall HR = 1.6,95%CI:1.33-1.92,P = 0.000).The results were consistent with when restriction to a 5 year lag time(HR = 1.84,95%CI:1.26-2.69,P = 0.002)and multivariable adjustment(HR = 1.96,95%CI:1.47-2.62,P = 0.000),but not for 10 year lag time(HR = 1.93,95%CI:0.9-4.16,P = 0.093)and brachytherapy subgroup(HR= 1.33,95%Cl:0.87-2.05,P = 0.188).The GRADE-relevant outcomes demonstrated that the absolute effect of RT on secondary BLCa was 17 per 1000 and 6 more per 1000 than non-RT.Conclusions:Patients received RT for PCa was associated with higher risks of developing secondary BLCa compared to patients with non-RT.