Patterns of failure after radical cystectomy for pT3-4 bladder cancer: Implications for adjuvant radiation therapy.

Abstract

370 Background: In patients with muscle-invasive bladder cancer, local-regional failure (LF) has been reported to occur in up to 20% of patients following radical cystectomy. The goals of this study were to describe patterns of LF, as well as assess factors associated with LF in a cohort of patients with pT3-4 bladder cancer. This information may have implications towards the use of adjuvant radiation therapy. Methods: Patients with pathologic T3-4 N0-1 bladder cancer were examined from an institutional radical cystectomy database. Preoperative demographics and pathologic characteristics were examined. Outcomes included overall survival and LF. Local-regional failures were defined using follow-up imaging reports and scans, and the locations of LF were characterized. Variables were tested by univariate and multivariable analysis for association with LF and overall survival. Results: 334 patients had pT3-4 and N0-1 disease after radical cystectomy and bilateral pelvic lymph node dissection. Of these, 46% received perioperative chemotherapy. The median age was 71 and median follow up was 11 months. On univariate analysis, margin status, pT stage, pN stage, and gender were all associated with LF (p < 0.05), however, on multivariable analysis, only pT and pN stage were significantly associated with LF (p < 0.01). Three strata of risk were defined, including low-risk patients with pT3N0 disease, intermediate-risk patients with pT3N1 or pT4N0 disease, and high-risk patients with pT4N1 disease, who had 2-year incidence of LF of 12%, 33%, and 72%, respectively. The most common sites of pelvic relapse included the external/internal iliac LNs and obturator LN regions. Notably, 34% of patients with LF had local-regional only disease at the time of recurrence. Conclusions: Patients with pT4 or N1 disease have a 2-year risk of LF that exceeds 30%. These patients may be the most likely to benefit from local adjuvant therapies.