Recently, Department of Hepatobiliary Surgery of the First Affiliated Hospital of Xi’an Jiaotong University (XJTU) along with 15 worldwide prestigious medical centers conducted a multi-center clinical trial of intrahepatic cholangiocarcinoma (ICC) and published an article entitled Number and Station of Lymph Node Metastasis After Curative-intent Resection of Intrahepatic Cholangiocarcinoma Impact Prognosis in Annals of Surgery. According to the TNM staging of American Joint Committee on Cancer (AJCC), the staging of ICC can be performed as below:
7th edition |
8th edition |
T category |
T1: solitary tumor without vascular invasion |
T1a: solitary tumor ≤5 cm without vascular invasion |
T1b: solitary tumor >5 cm without vascular invasion |
T2a: solitary tumor with vascular invasion |
T2: solitary tumor with intrahepatic vascular invasion or multiple tumors, with or without vascular invasion |
T2b: multiple tumors, with or without vascular invasion |
T3: tumor perforating the visceral peritoneum or involving local hepatic structures by direct invasion |
T3: tumor perforating the visceral peritoneum |
T4: tumor with periductal invasion |
T4: tumor involving local extrahepatic structures by direct invasion |
N category |
N0: no regional lymph node metastasis |
N0: no regional lymph node metastasis |
N1: regional lymph node metastasis present |
N1: regional lymph node metastasis present |
M category |
M0: no distant metastasis |
M0: no distant metastasis |
M1: distant metastasis |
M1: distant metastasis |
TNM stage |
I: T1 N0 M0 |
IA: T1a N0 M0 |
IB: T1b N0 M0 |
II: T2 N0 M0 |
II: T2 N0 M0 |
III: T3 N0 M0 |
IIIA: T3 N0 M0 |
IIIB: T4 and/or N1, M0 |
IVA: T4 N0 M0/any T, N1, M0 |
IV: any T, any N, M1 |
IVB: any T, any N, M1 |
Currently, the 8th edition of AJCC/Union for International Cancer Control (UICC) TNM staging system still has significant limitations. There is no definite opinion on whether routine lymph node resection should be performed during ICC surgery. Compared with gallbladder cancer, hilar cholangiocarcinoma and distal cholangiocarcinoma, the number of lymph node metastasis is defined as N0, N1 and N2. Nevertheless, in ICC stage, the N staging of lymph node is simply defined as N0 (without lymph node metastasis) and N1 (with lymph node metastasis). For patients undergoing lymphadenectomy, it is recommended to remove at least 6 lymph nodes according to the guidelines, which remains to be validated by clinical studies with a large sample. Although it is recommended to independently consider lymph node dissection in different regions for the ICC in the left and right lobes by the guidelines, which remains to be confirmed by large-sample-size clinical trials.
Professor Lyu Yi and Professor Zhang Xufeng from Department of Hepatobiliary Surgery of our hospital cooperated with other experts from 15 globally prestigious medical centers to obtain the following findings:
1. According to the number of positive lymph nodes, N staging of ICC can be further divided into N0 (no lymph node metastasis), N1(1-2 lymph node metastases) and N2 (≥3 lymph node metastases). The new N staging system can effectively distinguish the overall survival, disease-specific survival and recurrence-free survival of ICC patients.
2. When the total number of lymph node resection is ≥6, the maximum effectiveness for the assessment of overall survival of N0, N1 and N2 patients can be achieved. The above results have also been confirmed by the clinical data of 1036 ICC patients in SEER database.
3. When a sufficient number of lymph nodes has been resected (n≥6), the clinical prognosis of patients with lymph node metastasis beyond the 12th group lymph nodes is significantly worse than that of their counterparts with lymph node metastasis limited to the 12th group lymph nodes (median overall survival: 14 vs 24 months,HR=2.4). Therefore, the findings in the present study suggest at least 6 or more lymph nodes should be obtained for standard lymph node dissection during the resection of ICC. The station should include the lymph nodes beyond the 12th group lymph nodes to obtain accurate N staging. The new N staging (N0, N1 and N2) contributes to further optimizing the TNM staging system.
In July 2019, the team led by Professor Lyu Yi and Professor Zhang Xufeng conducted an international multi-center clinical trial related to pancreatic neuroendocrine tumor and published relevant outcomes inAnnals of Surgery. This is the second time that they publish a global multi-center clinical trial of ICC inAnnals of Surgery.
Article link:
https://journals.lww.com/annalsofsurgery/abstract/publishahead/number _ and _ station _ of _ lymph _ node _ meteorasis _ after.94701.aspx
https://www.ncbi.nlm.nih.gov/pubmed/31972643
