Characteristics and outcomes of patients with young-onset versus average-onset cholangiocarcinoma in the United States.

Abstract

4118 Background: Cholangiocarcinoma (CCA) is a lethal malignancy originating from the epithelium lining the biliary tree, with a rising incidence in the Western world. CCA is commonly diagnosed after the age of 50 years, referred to as average-onset CCA (AOCCA), which has known risk factors and predictors of overall outcomes. However, robust data regarding the characteristics and outcomes of patients with young-onset (diagnosed <50 years of age) CCA (YOCCA) are lacking. Methods: Data on patient characteristics, tumor characteristics, incidence, and mortality were retrieved from the SEER database spanning a period from the year 2000 to 2017 (representing 48% of the US population).Intrahepatic CCA (iCCA) was identified with a topography code of C22.0 (liver) and a histology code of 8140, 8160, 8161, 8480, 8481, or 8500 or with a topography code of C22.1 (intrahepatic bile ducts) and a histology code of 8000, 8010, 8020, 8140, 8160, 8161, 8260, 8480, 8481, 8490, or 8500. Extrahepatic CCA (eCCA) was identified with a topography code of C24.1 (extrahepatic biliary ducts) and a histology code of 8000, 8010, 8020, 8140, 8160, 8161, 8260, 8480, 8481, 8490, or 8500, or for any case with a topography code of C22.0, C22.1, or C24.0 and a histology code of 8162 (Klatskin tumor). A comparison was made between the patients with YOCCA and AOCCA. Trends in incidence were analyzed using the Joinpoint regression model. Overall survival distributions were estimated using the Kaplan-Meier method. Results: A total of 28,367 patients were included in the analysis, which included 2,082 (7.34%) patients with YOCCA. We noted an increase in the incidence of YOCCA over the study period (annual percentage change=+2.53, p=0.003). The majority of the patients in the YOCCA group were males (54.66%), White (50%), and had iCCA (71.9%). When compared to AOCCA, these patients were more likely to be males (54.7% vs 52.4%, p=0.048), non-White (39.8% vs 35.5%, p=0.007), and have a diagnosis of iCCA (71.9% vs 65.7%, p<0.0001). Patients in the YOCCA group were more likely to present with regional spread (31.6% vs 28.4%, p<0.0001) and metastatic disease (31.9% vs 25.6%, p<0.0001). YOCCA patients were also more likely to receive surgery (33.3% vs 22.7%, p<0.0001) and chemotherapy (62.6% vs 37.3%, p<0.0001) compared to patients in the AOCCA group. Patients with YOCCA had a significantly better median overall survival (13 months vs. 7 months, p<0.001) than patients with AOCCA. Conclusions: The current analysis showed a significant increase in the incidence of YOCCA over the 17 years of the study period. Patients with YOCCA were more likely to be non-White, males and present with iCCA. Despite presentation with advanced-stage disease (with regional spread or metastatic disease), patients with YOCCA were more likely to receive cancer-directed therapy and had better overall survival than patients with AOCCA.