Optimal Lymph Node Staging System in Evaluating Prognosis of Gallbladder Carcinoma: A Multi-institutional Study

Area of Science:

• Oncology
• Surgical Pathology
• Biostatistics

Background:

• Lymph node (LN) involvement is a critical prognostic factor in gallbladder carcinoma (GBC).
• Current LN staging systems, including AJCC 7th N staging, number of metastatic lymph nodes (NMLN), log odds of metastatic LNs (LODDS), and lymph node ratio (LNR), have limitations.
• Optimal categorization of nodal metastasis status remains controversial.

Purpose of the Study:

• To compare the discriminative abilities of different lymph node staging systems for gallbladder carcinoma (GBC).
• To identify the optimal lymph node staging system for predicting prognosis in GBC patients.

Main Methods:

• Retrospective analysis of 226 GBC patients who underwent curative-intent resection.
• Assessment of LN staging systems using tree-augmented naïve Bayesian (TAN), Cox proportional hazards regression, and binary logistic regression models.
• Comparison of model accuracy, fitness (C-index, AIC), and AUCs for each staging system.

Main Results:

• The number of metastatic lymph nodes (NMLN) was identified as the most important prognostic factor.
• NMLN-based prognostic models demonstrated superior accuracy (TAN: 88.15%), fitness (Cox: C-index 0.763), and AUC (0.872) compared to other systems.
• NMLN outperformed 7th N staging, LNR, and LODDS across all evaluated models.

Conclusions:

• The number of metastatic lymph nodes (NMLN) is the optimal lymph node staging system for evaluating prognosis in gallbladder carcinoma (GBC).
• NMLN provides a more accurate and reliable prediction of patient outcomes compared to existing staging methods.