The Epidemiology, Staging and Outcomes of Sarcomatoid Hepatocellular Carcinoma: A SEER Population Analysis

Hepatocellular carcinoma (HCC) subtypes differ in terms of histopathology and prognosis. Sarcomatoid HCC is rare and literature concerning the survival of patients with sarcomatoid HCC is scarce.

Data of patients with sarcomatoid HCC, diagnosed from 1989 to 2016, were extracted from the Surveillance, Epidemiology and End Results (SEER) database. We evaluated the baseline and tumor related data, overall survival (OS), disease-specific survival and the performance (Harrell's concordance index - OS c-index) of the eighth edition of the American Joint Committee on Cancer TNM staging system (AJCC8). In addition, univariate and multivariate forward stepwise cox regression analyses were performed to identify factors associated with increased risk of death.

The SEER cohort consisted of 71 patients, mostly males (n=49, 69.0%), of White race (n=51, 71.8%) and the most common stage at presentation was stage IVB (n=30, 42.3%). The overall predictive ability of AJCC8 was mediocre, with an OS c-index=0.577 (SE=0.048). Surgery (hazard ratio=0.25, p<0.001) was significantly associated with reduced risk of death. Advanced TNM stage was not associated with increased risk of death.

Sarcomatoid HCC, a rare subtype of HCC, is associated with poor outcomes in terms of overall and disease-specific survival across all disease stages. Surgery seems to be of utmost importance. The eighth edition of the AJCC8 for HCC underperforms in predicting the survival of patients with sarcomatoid subtype.