Urothelial carcinoma of the bladder with isolated lymph node metastasis: Natural history and outcomes following surgical resection.

Abstract

Although pathologic lymph node involvement carries a poor prognosis in patients with urothelial carcinoma of the bladder (UCB), a subset of patients may demonstrate durable survival following surgical resection. To this end, there are limited contemporary data describing the natural history of UCB in patients with isolated lymph node involvement (cN0pN+) following radical cystectomy (RC) with pelvic lymph node dissection (PLND). We therefore utilized a large, nationwide oncology dataset to examine the natural history and outcomes of cN0 pN+ UCB after surgical resection. We identified patients in the National Cancer Database (NCDB) with cN0 pN+ cM0 UCB from 2006 to 2015 treated with RC and PLND. The associations of baseline characteristics with all-cause mortality (ACM) were evaluated using Cox regression. A total of 2,884 patients formed the study cohort, including 42% with pN1 and 58% with pN2-3 disease. Of these, 606 (21%) received multiagent neoadjuvant chemotherapy, while 1,172 (41%) received postoperative adjuvant chemotherapy. A median of 15 (IQR 9-23) LNs were removed during PLND. The 5- and 7-year OS for the entire cohort were 20% and 17%, respectively. Compared to the overall cohort, patients surviving ≤5 years had lower pN stage (59% vs. 42% pN1) and lower pT stage (41% vs. 22% ≤pT2). On multivariable analysis, higher pT stage (HR 2.85, 95% CI 1.52-5.36 for pT3, HR 3.27, 95% CI 1.73-6.18 for pT4 vs. pT0), higher pN stage (HR 1.17, 95% CI 1.05-1.31 for pN2-3 vs. pN1), and increasing LN density (HR 2.37, 95% CI 1.88-2.99) were most strongly associated with increased ACM, while receipt of adjuvant chemotherapy (HR 0.61, 95% CI 0.55-0.68) was associated with reduced ACM. Although OS for patients with cN0 pN+ M0 UCB is poor, a subset of patients demonstrates durable long-term survival with 5- and 7-year OS of 20% and 17%, respectively. pT and pN stage represent important prognostic characteristics, while administration of adjuvant chemotherapy represents a potential therapeutic intervention associated with improved ACM.