Lymph node dissection during radical cystectomy following prior radiation therapy: results from the SEER database.

Purpose: Population studies of patients undergoing radical cystectomy (RC) for bladder cancer (BC) suggest that a more extended lymph node dissection (LND) increases survival. However, information regarding LNDs of patients undergoing RC with a history of radiation therapy for BC is largely unknown. This study aims to define the lymph node yield (LNY) in patients undergoing RC for BC following radiation of the bladder using the surveillance epidemiology and end results (SEER) database.

Methods: Data were collected using SEER 18 registries from 1988 to 2013 to identify patients undergoing RC for BC. Data on extent and yield of LND were obtained. Logistic regression and multivariate Cox proportional hazard regression were done to identify predictors of adequate LND and all-cause mortality, respectively.

Results: In total, 27,451 patients were identified, of which, 27,362 (99.7%) were radiation naïve and 89 (0.3%) had prior radiation therapy for BC. The average LNY in radiation naïve patients (15, SD [13.5]) was slightly higher than the LNY in patients with prior radiation (12.3 SD [9.2], p = 0.157). Prior radiation was not an independent predictor of overall mortality (HR = 1.3, 95% CI [0.98-1.7]; p = 0.076).

Conclusions: A lower proportion of patients with a history of radiation underwent a LND. The LNYs of radiation naïve patients, and those with a history of radiation, were not statistically different; however, the proportion of irradiated patients was small. Further investigation will be required to elucidate the patient and provider characteristics that contribute to the similar LNYs.