Prognostic factors in patients with intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second commonly-seen liver malignancy and one of the most fatal cancers in Taiwan. Survival after diagnosis of ICC remains poor. This study aimed to investigate the survival and prognostic factors in patients with ICC. All patients with newly diagnosed ICC during 2004 to 2018 were identified from a national cancer database and followed until December 2020. Estimates of overall survival (OS) were conducted using the Kaplan-Meier method and Cox proportional hazards model. Hazard ratios with 95% confidence intervals were calculated. Initially, 7940 patients with ICC disease (stage IV: 55.6%, 4418/7940) were eligible for this study. Only 32.3% (2563/7940) patients with ICC underwent liver resection. After Propensity score matching, 969 pairs (N = 1938) of patients were matched and selected (mean age 62.8 +/- 11.0 years, 53.1% were male, 29.7% had cirrhosis). The median follow-up time was 80.0 months (range 25-201 months). The 3-, 5-year OS rates were 44.0%, 36.4% in the surgical group and 26.0%, 23.7% in the non-surgical group, respectively. Surgery, young patients (<= 54 years), small tumor size, no vascular invasion and chemotherapy were associated with better OS in patients with stages I-III disease. Surgery benefit was maximum in stage I disease followed by stage II. In patients with stage IV disease, factors such as surgery, young patients (<= 64 years), single tumor, and no vascular invasion were associated with better OS. Chemotherapy was insignificantly associated with better OS. Long-term survival in patients with ICC is very poor. Compared to non-surgical patients, surgery conveys approximately 18% and 12% better OS rates at 3-year and 5-year, respectively. Early detection and surgical intervention may improve OS substantially in patients with ICC.