Fibrolamellar hepatocellular carcinoma (FL-HCC) epidemiology, survival characteristics, and outcomes: Surveillance, epidemiology, and end results database (SEER) study.

Abstract

e16213 Background: Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare and distinctive form of liver cancer that primarily affects adolescents and young adults without underlying liver disease. Unlike conventional HCC, it exhibits unique clinical and histological features and poses a diagnostic and therapeutic challenge. Using a national registry, we sought to evaluate the incidence, demographics, survival, and treatment characteristics of FL-HCC. Methods: We utilized the Surveillance, Epidemiology, and End Results (SEER) database to identify patients with microscopically confirmed FL-HCC between 2000-2020 using ICD-O-3 site code C22.0 and an 8171/3 histology code. The epidemiological characteristics included were age, gender, ethnicity, American Joint Committee on Cancer [AJCC] staging, annual income, and treatment modalities. The Kaplan-Meier survival curve was used to compare survival. Survival was stratified according to age, gender, race, stage, income, and treatment modalities. Multivariate analysis was done with Cox regression analysis on R programming language version 3.6.3. Results: We identified a total of 362 patients with fibrolamellar hepatocellular carcinoma with median age at diagnosis 27(8-84) years. It was found to be more common in males (62.2%) and among whites (78.2%). There was a striking increment in incidence with 1.9% in 2005 compared to 5.8% in 2020. The majority of the patients had stage IV disease (26.4%). Alpha-fetoprotein was noted to be positive only in 15.8% of patients. The majority of the patients received surgery (50.3%) and chemotherapy (48.1%) with a median time from diagnosis to treatment of 1.00 month (IQR: 0.00–1.00). A total of 11% of patients received radiation, and 25% received multiple treatments. Survival analysis revealed a median overall survival of 24.50 months (IQR: 7.00, 63.00), with a majority experiencing death attributable to the cancer diagnosis (60.2%). Median overall and cause-specific survival for stage I disease was 92 months, and stage IV disease was 21 months (p < 0.05). Patients below the age of 20 had a median survival of 85 months (95% CI: 41 to NA) compared to those aged between 20 and 59, i.e., 30 months (95% CI: 22 to 41 months). The higher-income categories, $55,000−59,999 (HR = 0.29, p = 0.05) and $60,000−64,999 (HR = 0.24, p = 0.03), demonstrated significantly lower hazards compared to < $35,000. We concluded that sex, location, and race did not influence the survival of FL-HCC. Conclusions: Our comprehensive analysis of FL-HCC revealed that diagnosis at a younger age, stage I disease, and higher annual income improved survival, whereas gender and race did not affect outcomes. Further collaborative efforts are warranted to advance our understanding of FL-HCC pathogenesis, optimize treatment strategies, and improve outcomes for affected individuals.