Better cancer-specific survival in young patients with nonmetastatic intrahepatic cholangiocarcinoma: A retrospective study of SEER database.

Abstract

e15637 Background: Intrahepatic cholangiocarcinoma (ICC) is a complicated and fatal malignancy. Aging plays a significant role in the occurrence and development of this liver cancer, but its prognostic role remains unclear. The purpose of this study is to compare the cancer specific survival (CSS) in young patients with elderly ones, and to further establish a nomogram, integrating age and other risk factors, to predict survival outcomes in ICC patients. Methods: Cases of intrahepatic cholangiocarcinoma diagnosed between 2004 and 2013 were extracted from SEER database. Patients were excluded if they had incomplete TNM staging, with distant metastasis (M1) or no evaluation on lymph node. The enrolled cases were divided into young (under 50 years of age) and elderly groups (50 years and over). 1-year and 3-year cancer CSS data were obtained. Kaplan-Meier methods were adopted and multivariable Cox regression models were built for the analysis of survival outcomes and risk factors. A predictive nomogram for prognosis was generated by software R, and the performance of the nomogram was assessed by C-index and validation curves. Results: There were 2385 patients meeting inclusion criteria with median follow up of 17.0 months. Compared with elderly group, young patients showed significantly higher pathological grading (P = 0.006), lower rate of lymph node invasion (P = 0.002), and early TNM stage (P = 0.005). The 1-year and 3-year CSS rates were 57.3% and 19.2% in young group, and 38.2% and 10.8% in elderly group. Both univariate analysis (P = 0.019) and multivariate analysis (P = 0.040) indicated significant difference of CSS between the two groups. The multi-factor, integrative nomogram was established to predict prognosis, whose predictive power was higher than the conventional tumor staging (AJCC 7thedition staging). And the calibration curves for the probability of 1- and 3-year CSS indicated that the nomogram-based prediction was in optimal agreement with actual observed survival. Conclusions: Compared with elderly patients, young patients with non-metastatic ICC appear to have more favorable clinicopathological characteristics and better prognosis.