Prognostic relevance of the lymph node ratio in surgical patients with extrahepatic cholangiocarcinoma.

AIM: Few studies have investigated the influence of the lymph node ratio (LNR), the ratio of the number of lymph nodes harboring metastatic cancer to the total number of lymph nodes removed, on the outcome after surgery for extrahepatic cholangiocarcinoma. This study was conducted to examine the prognostic impact of LNR in patients undergoing resection for extrahepatic cholangiocarcinoma. PATIENTS AND METHODS: We retrospectively analyzed a total of 60 consecutive patients who underwent resection for extrahepatic cholangiocarcinoma. We focused on the LNR, which was classified as 0 in 34 patients, between 0 and 0.2 in 13 patients, and greater than 0.2 in 13 patients. RESULTS: The overall five-year survival rates for patients with LNRs of 0, 0 to 0.2, and ≥0.2 were 44%, 10%, and 0%, respectively (p = 0.023). LNR was an independent predictive factor for estimated survival by both univariate (p = 0.016) and multivariate (p = 0.022) analyses including LNR, the sites of the primary tumors, and surgical margin as the variables. There were no statistically significant differences between patients who had less than 12 lymph nodes removed and those who had 12 or more lymph nodes removed (p = 0.484). CONCLUSION: LNR was a powerful, independent predictor of estimated survival in patients undergoing surgical resection for extrahepatic cholangiocarcinoma. LNR should be considered when stratifying patients for future clinical trials.