Adequate lymph node assessment for extrahepatic bile duct cancer: Do the data support the current AJCC recommendations?

4576 Background: AJCC staging manual 6th edition states that histologic examination of at least 3 lymph nodes (LN) is required for adequate N stage determination for extrahepatic bile duct cancer (EHBDCA). We hypothesize that this recommendation is insufficient and will lead to underestimation of N stage of EHBDCA. Methods: 257 patients (144 hilar [HCCA] and 113 distal [DCA] cholangiocarcinoma) who underwent curative intent resection for EHBDCA at our institution (1993 -2007) were analyzed. Final disease staging, including lymph node status and total number of nodes examined, was obtained from the pathology report. Differences in disease specific survival (DSS), according to nodal status, were compared using log rank test. R1 resections (n=51) were excluded from this analysis. Results: There were 89 patients (34.6%) with LN metastasis. On multivariate analysis, LN metastasis was an independent prognostic factor of poor survival (median DSS N0 vs N1: 53.3 months vs 19.3 months, p<0.0001, HR= 2.2 [95%CI: 1....