Precision Nodal Metrics in Gastrointestinal Cancers: A Narrative Review
Supreet KumarBackground and Aims:
Lymph node involvement remains one of the most powerful determinants of prognosis across gastrointestinal (GI) malignancies and constitutes a central component of the tumour-node-metastasis (TNM) staging system. Conventional nodal staging relies primarily on the absolute number of metastatic lymph nodes identified during pathological evaluation. However, this approach is highly dependent on the extent of lymphadenectomy and the adequacy of nodal retrieval, leading to potential stage migration and heterogeneity within individual nodal categories.
Objective:
To review the conceptual basis, methodological considerations and clinical implications of alternative nodal metrics, including lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS), in GI cancers and to examine their potential role in improving prognostic stratification beyond conventional TNM staging.
Evidence Acquisition:
A narrative review of the literature was performed focusing on studies evaluating nodal metrics in GI malignancies, including colorectal, gastric, pancreatic, oesophageal, biliary and hepatopancreatobiliary cancers. Emphasis was placed on studies examining the prognostic performance of LNR and LODDS, methodological issues related to nodal assessment and their integration into prognostic models.
Evidence Synthesis:
Evidence from multiple GI malignancies suggests that ratio-based and probabilistic nodal metrics may provide improved prognostic discrimination compared with traditional node-count-based staging systems, particularly in settings where nodal retrieval is limited or heterogeneous. LNR offers a clinically intuitive measure of metastatic density, while LODDS provides statistical robustness in scenarios of sparse nodal harvest or node-negative disease. These metrics have demonstrated value in survival modelling and prognostic nomograms across several tumour types.
Conclusions:
Alternative nodal metrics represent promising complementary tools for refining prognostic assessment in GI oncology. While the TNM classification remains the global standard for staging, incorporation of proportional and probabilistic nodal indices into prognostic models may enhance risk stratification and support more individualised prognostic assessment and risk-adapted treatment strategies.