Clinicopathologic and treatment characteristics of mixed hepatocellular carcinoma-intrahepatic cholangiocarcinoma (HCC-ICC).

e16218 Background: Mixed hepatocellular carcinoma-intrahepatic cholangiocarcinoma (HCC-ICC) represents a rare subtype of primary hepatic malignancy demonstrating morphological and biological features characteristic of both Hepatocellular Carcinoma (HCC) and Intrahepatic Cholangiocarcinoma (ICC). In this study, we describe the clinical and tumor characteristics of survival in HCC-ICC by using a large cohort. Methods: We selected patients diagnosed with HCC‐ICC, HCC, or ICC between 2011 and 2018 and were identified from the National Cancer Data Base (NCDB) using the International Classification of Diseases for Oncology codes. Baseline characteristics were delineated using percentages. Median overall survival (OS) was calculated using the Kaplan-Meier method. Demographic variables (age at diagnosis, gender, race, insurance status), comorbidity score, and treatment features were included. Short‐ and long‐term outcomes were evaluated through univariate analysis. Results: Out of 124,723 patients, 84.6% were diagnosed with HCC, 14.5% with ICC, and 1% with HCC‐ICC. Median survival was significantly better in HCC compared to HCC-ICC and ICC patients (16.2 months, 10.8 months, and 9.4 months, respectively, p < 0.001). Surgical intervention was used by 26.3% of HCC-ICC cases, 19.2% of ICC cases, and 9% of HCC cases. Multiagent chemotherapy was notably more utilized in ICC compared to HCC-ICC and HCC (42.6%, 22.8%, and 5.4%, respectively, p < 0.001). Meanwhile, single-agent chemotherapy was more commonly administered in HCC than in HCC-ICC and ICC (32.3%, 16.5%, and 11.4%, respectively, p < 0.001). Conclusions: HCC-ICC is an aggressive primary liver malignancy with a worse prognosis than HCC and ICC. The primary treatment approach for operable cases continues to be major hepatectomy combined with resection of hilar lymph nodes. Further research is urgently needed to better understand the exact role of the systemic therapies in managing HCC-ICC.