Pathological predictors for lymph node metastasis in T1 colorectal cancer

Purpose. To clarify pathological predictor for lymph node metastasis in T1 colorectal cancer. Methods. One hundred and sixty-four patients who underwent surgery for single T1 colorectal cancer were reviewed. The pathological differentiations of non-well differentiation, invasion depth (>= 2000 mu m), lymphatic channel involvement, venous invasion, and tumor budding were selected as candidate predictors. Tumor budding was estimated according to the definition proposed by Ueno et al. (Gastroenterology 2004; 127:385-394). The lymph node status was set for the endpoint. Logistic regression model was applied to analyze the predictors. Results. Lymph node involvement was observed in 9.8%. The positive rates were 13.4% for the pathological differentiations of non-well differentiation, 51.8% for invasion depth (>= 2000 mu m), 6.1% for lymphatic channel involvement, 8.5% for venous invasion, and 14.6% for tumor budding. The pathological differentiations of non-well differentiation (P < 0.001) and tumor budding (P = 0.002) were significantly associated with lymph node metastasis in multivariate analysis. When either two significant factors was adopted for the prediction of the lymph node metastasis, the sensitivity, specificity, positive predictive value, and negative predictive value were 94%, 82%, 36%, and 99%, respectively. Conclusion. The pathological differentiations of non-well differentiation and tumor budding are useful predictors for lymph node metastasis in T1 colorectal cancer.