Background: Combined hepatocellular carcinoma and cholangiocarcinoma (cHC) has wide histological diversity. We intended to investigate the prognostic influence of tumor types of cHC.
Methods: We analyzed the clinical and pathological features of cHC along 2010 WHO classification. Study group was 100 cHC patients who underwent primary resection. Control group comprised 200 propensity score-matched patients with intrahepatic cholangiocarcinoma (ICC).
Results: In cHC group, tumor diameter was 4.4 ± 2.8 cm and 95 patients had single tumor. They were classified as classical type in 46 and subtypes with stem cell (SC) features in 54. Subtypes with SC features included typical in 16, intermediate cell in 22, and cholangiolocellular in 16. Their 1- and 3-year tumor recurrence rates were 31.7 and 59.8%; and 1- and 3-year patient survival rates were 92.5 and 77.3%, respectively. Tumor recurrence (p = 0.008) and patient survival (p = 0.005) rates were different according to tumor types. Further stratification by subtypes with SC features resulted in prognostic stratification in tumor recurrence (p = 0.045) and patient survival (p = 0.042). However, tumor stage was the only independent risk factor for tumor recurrence and patient survival. Comparing with ICC control group, cHC group showed no significant difference in rates of tumor recurrence (p = 0.523), but better survival outcomes (p = 0.008). Median post-recurrence patient survival period was 20 months in cHC patients and 6 months in ICC patients (p = 0.001).
Conclusions: Our results indicated that there would be close relationship between the post-resection prognosis and histological types according to the 2010 WHO classification, but these histological types did not become an independent prognostic factor.