[Surgical treatment and survival analyses of intrahepatic cholangiocarcinoma]

Objective: To evaluate the survival benefit of surgical treatment for intrahepatic cholangiocarcinoma. Methods: This study is conducted based on the hepatobiliary tumor registry database. From May 2009 to December 2022,a total of 704 patients who were initially diagnosed with intrahepatic cholangiocarcinoma and underwent liver resection were consecutively enrolled at the Hepatobiliary Center of the First Affiliated Hospital of Nanjing Medical University. Among them,there were 380 males and 324 females,aged (M(IQR)) 61(15) years(range:27 to 88 years). Twenty-six (3.7%) patients received neoadjuvant therapy before surgery. The overall survival(OS) and disease-free survival(DFS) rates were estimated by life table method, and Kaplan-Meier survival curves were plotted. Log-rank test was used to compare the survival difference among tumor-node-metastasis(TNM) staging or three periods. The OS and DFS differences among lymph node groups or adjuvant treatment groups were quantified as HR with 95% CI estimated using Cox proportional-hazards model with adjustment for prognostic factors. Results: Among the 704 patients,349 cases(49.6%) underwent major hepatectomy (≥3 segments),331(47.0%) had lymph node resection during surgery,and 524 cases(74.4%) achieved R0 resection. The morbidity of Clavien-Dindo grade Ⅲ or higher complications was 16.5%(116/704),with a mortality rate of 3.0%(21/704) within 30 days post-surgery. The median OS time was 27.1 months, and the OS rates at 1-,3-,5- and 10-year were 69.1%, 42.4%,34.1% and 24.5%,respectively. The median DFS time was 10.5 months,and the corresponding DFS rates were 46.0%,25.4%,21.9% and 16.9%,respectively. According to the 8^th edition of AJCC staging system, the 5-year survival rates for ⅠA,ⅠB,Ⅱ,ⅢA,ⅢB and Ⅳ were 68.4%, 43.2%, 30.3%,32.2%,14.0% and 0,respectively. The corresponding DFS rates were 55.8%, 28.1%,13.8%,21.2%,3.3% and 0,respectively. There were no statistically significant differences of OS or DFS between stage ⅠB and Ⅱ, stage ⅠB and ⅢA, or between stage Ⅱ and ⅢA(Log-rank test:all P>0.05),while there were significant differences of OS and DFS among other stages(Log-rank test:all P<0.05). Using Cox model with adjustment for prognostic factors, there were no statistically significant differences of OS and DFS between non-lymphadenectomy group or the biopsy-N0 group and dissection-N0 group(both P>0.05). However,the overall and disease-free survival of the biopsy-N1 group or dissection-N1 group were worse than those of dissection-N0 group(both P<0.05),with overall survival being better in dissection-N1 group than biopsy-N1 group(P=0.017). Overall survival in the period from 2019 to 2022 were significantly superior to that during the periods from 2009 to 2013 and 2014 to 2018(both P<0.01). Adjusting for prognostic factors, the disease-free and overall survival of the postoperative adjuvant therapy group were significantly better than those of the observation group in the period 2019 to 2022(both P<0.01). Conclusions: Surgery remains a milestone for achieving long-term survival for patients with intrahepatic cholangiocarcinoma. Regional lymph node dissection is required for patients with lymph node metastasis. Adjuvant therapy can significantly reduce tumor recurrence and prolong overall survival.