Chronological analysis of surgical and oncological outcomes after the treatment of perihilar cholangiocarcinoma

Backgrounds/Aims: Despite advances in surgical techniques and perioperative supportive care, radical resection of hilar cholangiocarcinoma is the only modality that can achieve long-term survival.We chronologically investigated surgical and oncological outcomes of hilar cholangiocarcinoma and analyzed the factors affecting overall survival.Methods: We retrospectively enrolled 165 patients with hilar cholangiocarcinoma who underwent liver resection with a curative intent.The patients were divided into groups based on the period when the surgery was performed: period I ( 2005-2011) and period II (2012-2018).The clinicopathological characteristics, perioperative outcomes, and survival outcomes were analyzed.Results: The patients' age, serum CA19-9 levels, and serum bilirubin levels at diagnosis were significantly higher in the period I group.There were no differences in pathological characteristics such as tumor stage, histopathologic status, and resection status.However, perioperative outcomes, such as estimated blood loss (1528.8 vs. 1034.1 mL, p=0.020) and postoperative severe complication rate (51.3% vs. 26.4%,p=0.022), were significantly lower in the period II group.Regression analysis demonstrated that period I (hazard ratio [HR]=1.591;95% confidence interval [CI]=1.049-2.414;p=0.029), preoperative serum bilirubin at diagnosis (HR=1.585;95% CI=1.058-2.374;p=0.026), and tumor stage (III, IV) (HR=1.671;95% CI: 1.133-2.464;p=0.010) were significantly associated with poor prognosis.The 5-year survival rate was better in the period II patients than in the period I patients (35.1% vs. 21.0%,p=0.0071).Conclusions: The surgical and oncological outcomes were better in period II.Preoperative serum bilirubin and advanced tumor stage were associated with poor prognosis in patients with hilar cholangiocarcinoma.(