Predictors and patterns of recurrence after curative liver resection in intrahepatic cholangiocarcinoma, for application of postoperative radiotherapy: a retrospective study

BACKGROUND The majority of patients with intrahepatic cholangiocarcinoma (IHCC) who undergo complete tumor resection subsequently develop tumor recurrence. The objectives of this study were to determine the risk factors for IHCC recurrence after curative (R0) liver resection and to identify the feasibility about postoperative adjuvant radiation therapy (RT). METHODS We retrospectively reviewed patients who underwent liver resection for IHCC between April 1995 and December 2012 at Samsung Medical Center. Cox regression analysis was performed to determine risk factors of recurrence. Patients with a recurrence in remnant liver within 2 cm from the resection margin, with or without locoregional lymph node (LN) metastases, were considered as potential RT candidates. Center-of-mass (COM) distances between the recurrent cancers and the cut surface were measured with MATLAB. RESULTS We included 153 out of 198 patients who underwent partial liver resection for IHCC. About two thirds (n=93, 60.8%) of patients developed recurrent disease. The median recurrence-free survival (RFS) was 14 months (range, 0-204). Tumor size≥4.0 cm, LN metastasis and multiple tumors were significant predictors of IHCC recurrence on multivariate analysis. Tumor size≥5.0 cm was the only factor associated with recurrence beyond the RT field in patients with recurrence. Among 93 patients with recurrence, 16 (17.2%) patients were recurred in the RT field. CONCLUSION After curative resection in IHCC, more than 60% of patients recurred, and among recurred patients, 17.2% were recurred within the RT field. Consequently, for control of locoregional recurrence, adjuvant RT could be carefully considered in patients with recurrence factors. Especially, patients with a tumor size larger than 5 cm should be judiciously selected for adjuvant RT.