Combined Hepatocellular Cholangiocarcinoma: A Population-Based Retrospective Study.

ABSTRACT

OBJECTIVES: Combined hepatocellular cholangiocarcinoma (CHC) is a rare form of primary liver cancer with features of hepatocellular carcinoma and cholangiocarcinoma. The objective of this study was to investigate the incidence, demographics, tumor characteristics, treatment, and survival of patients with CHC. METHODS: Data on CHC between 2004 and 2014 were extracted from the Surveillance, Epidemiology, and End Results Registry and analyzed. RESULTS: Five hundred twenty-nine patients with CHC were identified; 367 were male. Median age at diagnosis was 62.5 ± 12 years. The overall incidence of CHC between 2004 and 2014 was 0.05 per 100,000 per year. Incidence increased with age, with the highest incidence in men occurring between 60 and 64 years and 75-79 years for women. Women had a higher incidence of CHC compared to men (0.08 vs 0.03 per 100,000 per year). Most tumors were poorly differentiated (30.8%) while the most common stage at presentation was stage 4 (26.8%). 39.5% of these tumors were resected while 6.8% received radiation and 34% received chemotherapy. One- and 5-year cause-specific survival for CHC was 41.9% and 17.7%, respectively, with a median survival of 8 months. Worse outcomes were noted among patients with tumor stage 3 (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.44-2.87, P = 0.000), stage 4 (HR 1.71, 95% CI 1.06-2.75, P = 0.027), those not treated with surgery (HR 4.94, 95% CI 3.64-6.68, P = 0.000), those who did not receive radiation (HR 1.71, 95% CI 1.08-2.70, P = 0.021), those who did not receive chemotherapy (HR 1.54, 95% CI 1.20-1.99, P = 0.001), and those with increasing tumor size on chemotherapy (HR 1.00, 95% CI 1.00-1.00, P = 0.013). DISCUSSION: CHC is the combined presentation of 2 malignancies. Incidence appears to be increasing and is associated with age and male gender. While surgery, radiation, and chemotherapy are associated with improved outcomes, patients who did not undergo surgery are at highest risk for death.