Discordance between conventional and detailed lymph node analysis in resected biliary carcinoma at or above the cystic duct: Are we understaging patients?

Background. Analysis of portal lymph node (LN) metastases following resection of biliary carcinomas at or above the cystic duct (BC) is used to select patients for adjuvant therapy, but no guidelines exist and LN yield is low. Some consider analysis of 7 LNs necessary for accurate staging. Conventional LN analysis may understage patients. Methods. Portal LNs from 38 node-negative patients following resection of BC from 2000 to 2008 were reexamined in detail for occult metastases (OM) using a modified Weaver protocol. Outcomes measured were discordance in LN positivity and patient survival. Results. On detailed examination, 5 of 38 patients had OM. There was no difference in survival between patients with and without OM (24 vs 17 months; p = .382). There was no association between OM and patient demographics or adverse tumor characteristics. The median LN yield was 3. Of the 27 patients with\7 LNs retrieved, 1 had OM, compared with 4 of 11 patients with C7 LNs retrieved (p = .030). OM in these well-staged patients were associated with reduced survival (9 vs 41 months; p = .032). Conclusions. There is discordance between conventional and detailed LN analysis in resected BC. LN yield C7 was associated with OM. The presence of OM may be associated with decreased survival. Conventional LN analysis may understage patients with resected BC.