Clinicopathological Characteristics and Clinical Course of Non-muscle-invasive Bladder Cancer Secondary to Radical...

The clinical course and clinicopathological characteristics of primary non-muscle-invasive bladder cancer (NMIBC) have been well characterized; however, those of NMIBC secondary to radical nephroureterectomy (RNU) remain unclear. We aimed to compare these parameters between NMIBC following RNU and primary NMIBC.

The records of patients who underwent transurethral resection of bladder tumor and were later diagnosed with NMIBC between January 2009 and December 2016 were retrospectively analyzed. Patients who underwent RNU for upper tract urinary carcinoma (UTUC) and subsequently developed NMIBC were included in the UTUC-NMIBC group. Patients who were newly diagnosed with NMIBC were included in the primary NMIBC group. The clinicopathological characteristics and recurrence-free survival rates in patients were compared between the groups using Pearson's chi-squared test and the Kaplan-Meier method with the log-rank test, respectively. Further, the predictors of recurrence-free survival were identified using Cox proportional hazards regression analysis.

A total of 59 and 1,019 patients were included in the UTUC-NMIBC and primary NMIBC groups, respectively. Significant differences were observed between the groups in tumor stage, grade, largest tumor size, and presence of carcinoma in situ. Additionally, patients in the UTUC-NMIBC group exhibited significantly poorer recurrence-free survival than those in the primary NMIBC group (p=0.0035). Univariate and multivariate Cox regression analysis revealed differences in the predictors of recurrence-free survival between the patients in both groups.

NMIBC secondary to RNU exhibits distinct tumor characteristics and recurrence-free survival compared with primary NMIBC. Further studies are needed to clarify the mechanisms underlying these differences.