Comparison of the new American Joint Committee on Cancer substratification in node-negative pT2 urothelial carcinoma of the bladder: analysis of patient outcomes in a contemporary series.

Abstract

• To determine whether there is a difference in survival in patients with node-negative pT2a vs pT2b urothelial carcinoma of the bladder (UBC), as recent studies suggest that the new American Joint Committee on Cancer substratification may not have prognostic significance. • Of 252 patients undergoing radical cystectomy (RC) and extended bilateral pelvic lymphadenectomy (ePLND) between 1999 and 2009, 72 (28.6%), with a mean (range) age of 66 (44-83) years (50 men, 22 women), had pathologically confirmed pT2 UCB. • Fisher's exact test and Cox regression analysis were used for uni- and multivariate analysis of risk factors of recurrence at a median (range) follow-up of 28 (2.2-115.7) months. • Kaplan-Meier plots were used to estimate the impact of pT2 substratification in lymph node (LN)-negative disease on recurrence-free (RFS) and cancer-specific (CSS) survival using log-rank test. • Of the 72 patients, 39 had pT2a (54.2%) and 33 pT2b UCB (45.8%) on definitive histological examination. The median (range) number of LNs removed was 19 (6-38) in pT2a and 22 (4-36) in pT2b (P = 0.31) UCB. • At RC, there was LN-positive disease in one patient with pT2a UCB, whereas seven patients with pT2b UCB had LN-positive disease (P = 0.02). • The median (range) number of LNs removed in LN-positive disease was 18 (11-30) and in LN-negative disease was 20 (4-38) (P = 0.52). • In LN-negative disease, actuarial 5-year RFS was 85.9% in patients with pT2a UCB vs 37.5% in those with pT2b UCB (P < 0.001). Actuarial 5-year CSS was 84.8% in patients with LN-negative pT2a UCB vs 59.6% in patients with LN-negative pT2b UCB (P = 0.01). • In Cox regression analysis, pT2 substratification was the only independent risk factor of recurrence and cancer-specific death (P < 0.001 and P = 0.008). • In this contemporary series of patients undergoing RC with ePLND, there was a significant difference in RFS and CSS between LN-negative pT2a and pT2b UCB, and pT2 substratification was the only risk factor of recurrence and cancer-specific death. • These data are supportive of the current concept of substratification in LN-negative pT2 UCB.