Optimal extent of surgical and pathologic lymph node evaluation for resected intrahepatic cholangiocarcinoma

Lymph node (LN) status is an important predictor of overall survival for resected IHCC, yet guidelines for the extent of LN dissection are not evidence-based. We evaluated whether the number of LNs resected at the time of surgery is associated with overall survival for IHCC.

Patients undergoing curative-intent (R0 or R1) resection for IHCC between 2004 and 2012 were identified within the US National Cancer Database. LN thresholds were evaluated using maximal chi-square testing and five-year overall survival was modeled using Kaplan-Meier and Cox regressions.

57% (n = 1,132) of 2,000 patients had one or more LNs resected and pathologically examined. In the 631 patients undergoing R0 resection with pN0 disease, maximal chi-square testing identified ≥3 LNs as the threshold most closely associated with overall survival. Only 39% of resections reached this threshold. On multivariable survival analysis, no threshold of LNs was associated with overall survival, including ≥3 LNs (p = 0.186) and the current American Joint Committee on Cancer recommendation of ≥6 LNs (p = 0.318).

In determining the extent of lymphadenectomy at the time of curative-intent resection for IHCC, surgeons should carefully consider the prognostic yield in the absence of overall survival benefit.