A novel N-stage classification system could better predict survival for patients with cholangiocarcinoma (CCA) compared to the current 8th Edition of the American Joint Committee on Cancer (AJCC), according to a recent study in Frontiers in Oncology.
“In summary, the current study demonstrated that patients with more positive LNs had poorer survival,” the authors wrote.
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The study included a cohort of 675 patients previously diagnosed with CCA who underwent surgical resection between 2004 and 2015. The authors aimed to establish an optimal cut-off point for the number of metastatic lymph nodes (MLNs) and subsequently create a modified AJCC staging system based on this new N category. Patients meeting strict inclusion criteria were analyzed for various clinicopathological variables, including race, gender, tumor differentiation, age, tumor size, and survival outcomes.
The proposed modified nodal category, which categorizes patients into 3 groups—N0 (no MLN), N1 (1 to 3 MLNs), and N2 (4 or more MLNs)—showed notable differences in overall survival, suggesting its potential as an independent prognostic factor. Statistical analyses indicated that this new staging system exhibited improved discriminatory power compared to the existing AJCC system.
The AJCC staging system for CCA traditionally did not incorporate the number of MLNs, unlike similar classifications for other carcinomas. The study emphasizes the potential significance of MLNs in determining CCA prognosis, echoing previous research that suggested patients with multiple MLNs experienced worse outcomes.
“Besides, compared with the existing ICC staging systems, the new staging system described herein can obtain more accurate risk stratification, which could be considered for inclusion in the next version of the AJCC staging system,” the authors suggested.
The necessity of routine lymph node dissection (LND) in CCA remains an ongoing debate. The research suggests that adequate LND could potentially lead to extended survival and more accurate patient stratification.
The study indicates that harvesting at least 6 lymph nodes may be essential to ensure accurate staging. Likewise, the dissection of the hepatoduodenal ligament and the common hepatic artery nodes are crucial for optimum staging, as MLNs spread to these nodes in 80% of the cases.
While this research introduces a modified nodal classification system for CCA and addresses a notable gap in the current staging methodology, it’s essential to acknowledge the limitations inherent in any study. Incomplete data on resection margin status and lack of information on recurrent disease were noted as potential limitations of the study.
Liao S, Liao R, Wu H, Wang S, Zhou Y. Proposal for a new N-stage classification system for intrahepatic cholangiocarcinoma. Front Oncol. Published online August 11, 2023. doi:10.3389/fonc.2023.1149211