Extramural venous invasion as an independent predictor of lymph node metastasis in colon adenocarcinoma: a multivariate analysis

Introduction Lymph node metastasis (LNM) is a key determinant of prognosis and treatment decisions in colon adenocarcinoma. Among histopathological features associated with tumor aggressiveness, extramural venous invasion (EMVI) has been increasingly recognized as an adverse factor; however, its independent role in predicting nodal metastasis remains incompletely defined. Material and Methods In this retrospective study, 180 consecutive patients who underwent primary surgical resection for colon adenocarcinoma, excluding rectal tumors, neoadjuvant-treated cases, and histological subtypes other than adenocarcinoma NOS, were evaluated. Histopathological parameters, including EMVI, intramural venous invasion, lymphovascular invasion (LVI), perineural invasion (PNI), tumor budding, and tumor deposits, were systematically reviewed, and elastic staining was used in equivocal cases. Associations with LNM were analyzed using univariate and multivariate logistic regression. Results Lymph node metastasis was identified in 47.8% of patients, and EMVI was present in 21.7% and was significantly more frequent in patients with nodal metastasis. In multivariate analysis, LVI was the strongest independent predictor of LNM, followed by PNI, EMVI, and high tumor budding. The model demonstrated good calibration and an overall accuracy of 80%. Conclusions Extramural venous invasion is an independent predictor of LNM and reflects a biologically aggressive tumor phenotype. Its routine assessment, together with other high-risk features, may improve risk stratification and support more informed clinical decision-making.