Is Radiotherapy Warranted Following Intrahepatic Cholangiocarcinoma Resection? The Impact of Surgical Margins and Lymph Node Status on Survival

Background. The role of radiotherapy (RT) for surgically resected intrahepatic cholangiocarcinoma (ICC) remains poorly defined. Radiotherapy is often considered when positive resection margins exist. The present study sought to examine the impact of radiotherapy following ICC resection. Methods. Patients with early-stage disease, who underwent surgical resection, were identified from the National Cancer Database (1998-2013). Patients were stratified by the receipt of RT. Survival outcomes were examined following propensity score matching (PS), and a Cox regression for survival analysis was used to examine predictors of survival. Results. A total of 2897 patients were identified. R0 status was achieved in 1951 patients (67.3 %). RT was delivered to 525 patients (R0 = 255, R1/R2 = 230, unknown = 43). Following PS matching, the overall survival for R0 versus R1/R2 resection was 31.2 versus 19.5 months (p < .001), respectively. RT was associated with a trend toward improved survival for R1/R2 lymph node negative patients (39.5 vs. 21.1 months; p =.052). In a multivariate model accounting for different patient and disease characteristics, RT was not associated with survival. In contrast, age, comorbidities, tumor grade, resection margins, lymph nodes status, and tumor's T stage were identified as negative predictors of survival. Conclusions. Patients with negative resection margins demonstrated improved survival outcome among ICC patients. In patients with positive resection margins and node negative disease, radiotherapy did not provide a survival benefit. Further studies are warranted to confirm and further define these results.