Nomograms predict survival outcome of Klatskin tumors patients

Abstract

Objective: Klatskin tumors are rare, malignant tumors of the biliary system with a poor prognosis for patient survival. The current understanding of these tumors is limited to a small number of case reports or case series; therefore, we examined prognostic factors of this disease.

Methods: A population cohort study was conducted in patients selected from the Surveillance, Epidemiology, and End Results (SEER) database with a Klatskin tumor that was histologically diagnosed between 2004 to 2014. Propensity-matching (PSM) analysis was performed to determine the overall survival (OS) among those with a Klatskin tumor (KCC), intrahepatic cholangiocarcinoma (ICCA), or hepatocellular carcinoma (HCC). The nomogram was based on 317 eligible Klatskin tumor patients and its predictive accuracy and discriminatory ability were determined using the concordance index (C-index).

Results: Kaplan-Meier analysis showed that patients with Klatskin tumors had significantly worse overall survival rates (1-year OS = 26.2%, 2-year OS = 10.7%, 3-year OS = 3.4%) than those with intrahepatic cholangiocarcinoma (1-year OS = 62.2%, 2-year OS = 36.4%, 3-year OS = 19.1%, p < 0.001) or hepatocellular carcinoma (1-year OS = 72.4% , 2-year OS = 48.5%, 3-year OS = 36.2%, p < 0.001). A poor prognosis was also significantly associated with older age, higher grade, SEER historic stage, and lymph node metastasis. Local destruction of the tumor (HR = 0.635, 95% CI [0.421-0.956], p = 0.03) and surgery (HR = 0.434, 95% [CI 0.328-0.574], p < 0.001) were independent protective factors. Multivariate Cox analysis showed that older age, SEER historic stage, and lymph node metastases (HR = 1.468, 95% CI [1.008-2.139], p = 0.046) were independent prognostic factors of poor survival rates in Klatskin tumor patients, while cancer-directed surgery was an independent protective factor (HR = 0.555, 95% CI [0.316-0.977], p = 0.041). The prognostic and protective factors were included in the nomogram (C-index for survival = 0.651; 95% CI [0.607-0.695]).

Conclusions: The Klatskin tumor group had poorer rates of OS and cancer-specific survival than the ICCA and HCC groups. Early detection and diagnosis were associated with a higher rate of OS in Klatskin tumor patients.

Keywords: Hepatocellular carcinoma; Hilar cholangiocarcinoma; Historic stage; Intrahepatic cholangiocarcinoma; Klatskin tumor; Lymph node metastases; Nomograms; Surgery; Surveillance, epidemiology and end results database; Survival.