Fibrolamellar Hepatocellular Carcinoma: A Population-Based Observational Study.

Background: In the USA, fibrolamellar hepatocellular carcinoma (FLC) accounts for 1-2% of all cases of hepatocellular carcinoma. FLC remains poorly understood.

Aim: We aim to investigate the incidence, demographics, tumor characteristics, treatment, and prognosis of patients with FLC.

Methods: Data on FLC between 2000 and 2016 were extracted from the SEER database and analyzed.

Results: A total of 300 patients with FLC were identified where 126 were male. Median age at diagnosis was 27 ± 22 years. The overall age-adjusted incidence of FLC between 2000 and 2016 was 0.02 per 100,000 per year. A bimodal distribution was observed where the highest incidences occurred between 15-19 years and 70-74 years. Most tumors on presentation were moderately differentiated (20.7%), while the most common stage at presentation was stage 1 (21.7%) followed by stages 3 and 4 (20.0% and 20.3%, respectively); 50.3% of these tumors were surgically resected, while 8.0% received radiation and 45.3% received chemotherapy. One- and 5-year cause-specific survival for FLC was 72.0% and 32.9%, respectively, with a median survival of 32.9 months. HCC had a median survival time of 11.7 months. Patients who were not treated with surgical intervention had about 3 times increased risk for death (HR 2.8, 95% CI 1.68-4.72, P = 0.000). Radiation and chemotherapy did not significantly affect outcomes.

Conclusion: FLC presents with a bimodal distribution in both early and elderly individuals. Compared to HCC, FLC has a higher recurrence rate but better survival outcome. Surgical intervention is superior to chemotherapy and radiation.