Prophylactic Intravesical Chemotherapy to Prevent Bladder Recurrence After Nephroureterectomy for Primary Upper Tract Urothelial Carcinoma Patients

INTRODUCTION

Upper tract urothelial carcinomas (UTUC) are relatively uncommon compared to bladder cancer and account for only 5-10% of urothelial carcinomas, with an estimated annual incidence in Western countries of ~2 cases per 100,000 inhabitants. In 17% of cases, concurrent bladder cancer is present. Recurrence in the bladder after management of UTUC occurs in 22-47% of UTUC patients, compared with 2-6% in the contralateral upper tract. At our institution, we reported that 30.8% of UTUC patients developed intravesical recurrence, which was in line with the global trend.

Generally speaking, the field cancerization hypothesis and intraluminal seeding are currently the two main concepts to explain multifocality of urothelial cancer and the recurrent bladder tumor. Independent multiclonal tumor development after carcinogenic exposure of the entire urothelial and intraluminal implantation followed by clonally induced single progenitor cell evolution are the mechanisms suggested. While the two mechanisms could co-exist, the intraluminal seeding hypothesis is becoming more prevalent with the emergence of more evidence from molecular studies. Thus postoperative intravesical chemotherapy could potentially remove the implantation cell and prevent recurrence. While intravesical instillation is widely used to prevent recurrence after transurethral resection for primary bladder tumors, there is still no consensus on the prophylactic capability of intravesical chemotherapy in preventing bladder recurrence after nephroureterctomy for UTUC. According to a previous prospective, multicentre, randomised clinical trial, a single postoperative dose of intravesical mitomycin C appears to reduce the risk of a bladder tumour within the first year following nephroureterectomy for UTUCs.

AIM OF THE WORK This clinical trial is designed to evaluate the efficacy of single immediate intravesical chemotherapy instillation in the prevention of bladder recurrence after nephroureterectomy for UTUCs.