Survival analysis and prognostic nomogram for patients undergoing resection of extrahepatic cholangiocarcinoma.

BACKGROUND: Tumor location of extrahepatic cholangiocarcinoma (CCA) might influence survival after resection. METHODS: A consecutive series of 175 patients who had undergone a potentially curative resection of extrahepatic CCA was analyzed. We calculated concordance indices of different constructed prognostic models for survival including TNM (tumour-node-metastasis) staging and developed a nomogram of the most sensitive model. RESULTS: Overall cancer-specific survival rates were 83%, 58%, and 26% at 1, 2, and 5 years, respectively. Cancer-specific survival according to location was 42% for proximal, 23% for mid, and 19% for distal CCA after 5 years. Tumor location was not an independent significant predictor (P = 0.06). A prognostic model using all potential prognostic variables predicted survival better compared with TNM staging (concordance index 0.65 versus 0.63). A reduced model containing only lymph node status, microscopically residual tumor status, and tumor differentiation grade, also outperformed TNM staging (concordance index 0.66). CONCLUSIONS: Tumor location of extrahepatic CCA does not independently predict cancer-specific survival after resection. We developed a nomogram, based on a prognostic model with lymph node status, microscopically residual tumor status of resection margins, and tumor differentiation grade, that predicted survival better than TNM staging.