Prognostic Nomogram for Intrahepatic Cholangiocarcinoma After Partial Hepatectomy

TLDR

The study aimed to develop a prognostic nomogram for intrahepatic cholangiocarcinoma patients following partial hepatectomy. The authors constructed the nomogram from a retrospective cohort of 367 ICC patients, identified independent prognostic factors, and evaluated its predictive accuracy using concordance indices and calibration curves, comparing it to five existing staging systems and validating it with bootstrap resampling and a prospective cohort of 82 patients. The nomogram achieved a concordance index of 0.74, outperforming all five staging systems, with calibration curves showing good agreement and superior discrimination in both the derivation and validation cohorts, indicating more accurate prognostic prediction for ICC after partial hepatectomy.

Abstract

This study aimed to establish an effective prognostic nomogram for intrahepatic cholangiocarcinoma (ICC) after partial hepatectomy.The nomogram was based on a retrospectively study on 367 patients who underwent partial hepatectomy for ICC at the Eastern Hepatobiliary Surgery Hospital from 2002 to 2007. The predictive accuracy and discriminative ability of the nomogram were determined by concordance index (C-index) and calibration curve and compared with five currently used staging systems on ICC. The results were validated using bootstrap resampling and a prospective study on 82 patients operated on from 2007 to 2008 at the same institution.On multivariate analysis of the primary cohort, independent factors for survival were serum carcinoembryonic antigen, CA 19-9, tumor diameter and number, vascular invasion, lymph node metastasis, direct invasion, and local extrahepatic metastasis, which were all selected into the nomogram. The calibration curve for probability of survival showed good agreement between prediction by nomogram and actual observation. The C-index of the nomogram for predicting survival was 0.74 (95% CI, 0.71 to 0.77), which was statistically higher than the C-index values of the following systems: American Joint Committee on Cancer (AJCC) seventh edition (0.65), AJCC sixth edition (0.65), Nathan (0.64), Liver Cancer Study Group of Japan (0.64), and Okabayashi (0.67; P < .001 for all). It was also higher (0.74) in predicting survival for the mass-forming type of ICC (P < .001). In the validation cohort, the nomogram discrimination was superior to the five other staging systems (C-index: 0.75 v 0.60 to 0.63; P < .001 for all).The proposed nomogram resulted in more-accurate prognostic prediction for patients with ICC after partial hepatectomy.