Adjuvant chemotherapy following curative intent hepatectomy for intrahepatic cholangiocarcinoma: Results from a multi-institutional analysis of 575 patients.

4110 Background: Surgical resection alone is the standard of care for patients with resectable intrahepatic cholangiocarcinoma (IHC). This study evaluates the benefit of adjuvant chemotherapy (AdjCTx) following curative intent hepatectomy for IHC. Methods: Clinicopathologic and long-term outcome data of 575 consecutive patients treated with curative intent hepatectomy for IHC (1995-2011) were extracted from a multi-institutional registry. After excluding operative mortality and M1 (n=46), Cox regression analysis was used to identify independent determinants of early recurrence (i.e., within 3 years). Propensity scores, which are used in observational studies to reduce selection bias by equating groups on the basis of relevant covariates, were calculated and utilized to match patients who had or had not AdjCTx (one-to-one match). Cases whose propensity score deviated more than 0.10 were considered unmatched and excluded from the analysis. Primary end-point was recurrence-free survival (RFS) at 3-years. Results: At a median FU of 42 months, 247 patients had recurred. Predictors of recurrence were LN metastases (HR 1.83 [1.36-2.44]), radical resection (HR 0.64 [0.45-0.9]), an elevated preoperative CA19.9 (HR 1.54 [1.15-2.07]), vascular invasion (HR 1.97 [1.49-2.61]), multiple tumors (HR 2.21 [1.71-2.86]), and size (analysed as continuous variable) (HR 1.01 [1.01-1.01]). After matching, no difference was observed between patients who had or had not AdjCTx (n=155 per group; 3-yrs RFS 28.3% vs. 38.0%, respectively; p=NS). When the analysis was restricted to patients who had gemcitabine, GEMOX or FOLFOX for 3 or more cycles (n=64 per group) again no difference emerged between patients who had or had not AdjCTx (3-yrs RFS 27.7% vs. 40.0% respectively, p=NS ). Conclusions: Our data suggest that AdjCTx following resection of IHC does not increase 3-years RFS.