Lymph node yield at radical cystectomy predicts mortality in node-negative and not node-positive patients.
OBJECTIVE
To better define the relationship between lymph node count and survival in patients undergoing radical cystectomy for bladder cancer by identifying and controlling for key confounding variables in a large population-based cohort. Considerable controversy remains regarding the correlation between node count and survival, and most prior analyses have not accounted for both patient and provider factors.


METHODS
The Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database was used to identify patients with urothelial bladder carcinoma who underwent radical cystectomy from 1992 to 2006. Patients were divided into 2 cohorts based on the presence or absence of nodal metastases, and we performed Cox regression analyses to evaluate the association between node count and survival. Covariates included age, Charlson comorbidity index, stage, grade, lymph node density, number of positive nodes, urinary diversion, chemotherapy, year of surgery, transfusion, and surgeon volume.


RESULTS
The cohort consisted of 2391 node-negative and 779 node-positive patients. In node-negative patients, individuals with low node counts had significantly worse overall survival (OS) and disease-specific survival (DSS) compared to the highest node count tertile. In node-positive patients, node count was not an independent predictor of OS or DSS.


CONCLUSIONS
Lymph node count at radical cystectomy is associated with both OS and DSS in patients without nodal metastases. However, in patients with node-positive disease, node count is not an independent predictor of survival suggesting that it is likely a proxy for other patient and provider factors in these individuals.
Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA. todd.morgan@vanderbilt.edu
Todd M
TM
Morgan
Daniel A
DA
Barocas
David F
DF
Penson
Sam S
SS
Chang
Shenghua
S
Ni
Peter E
PE
Clark
Joseph A
JA
Smith
Michael S
MS
Cookson
D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D015653:Cystectomy / Q000379:methods; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D011379:Prognosis; D015996:Survival Rate; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*