Clinicopathological Factors and Nomogram Development for Predicting Lymph Node Metastasis in Locally Advanced Rectal Cancer

BACKGROUND: Research on lymph node metastasis (LNM) in locally advanced rectal cancer (LARC) remains significantly underexplored. This study investigates the clinicopathological factors associated with LNM in LARC and develops a predictive nomogram for clinical application. METHODS: A retrospective analysis was performed on 1270 patients with LARC who underwent radical surgery between 2018 and 2023. Univariate and multivariate logistic regression analyses were conducted to identify independent predictors of LNM. A nomogram integrating these predictors was constructed and internally validated using bootstrap resampling. Subgroup analyses were carried out to compare stage N1 (n=333) and stage N2 (n=265) patients to determine the risk factors for advanced metastasis. RESULTS: The detection rate of LNM was 47.0% (598/1270). Independent risk factors included mucinous adenocarcinoma (OR=1.529, P =0.018), bowel obstruction (OR=1.418, P =0.014), poor tumor differentiation (OR=2.468, P