Evaluation of venous invasion by Elastica van Gieson stain and tumor budding predicts local and distant metastases in patients with T1 stage colorectal cancer.

Evaluation of pathologic predictors of metastases in T1 stage colorectal cancer may be difficult with hematoxylin and eosin (HE) staining alone. The aim of this study was to clarify the role of pathologic predictors by using immunohistochemical staining and Elastica van Gieson (EVG) staining. One hundred and twenty-four patients who underwent bowel resection for single T1 stage colorectal cancer from 1990 to 2004 in 1 institution were studied. D2-40, EVG staining, and CAM5.2 were used to detect lymphatic invasion, venous invasion, and tumor budding, respectively. These 3 factors were separately evaluated based on HE staining. Histology was reviewed by 1 pathologist. Lymph node metastases in the surgical specimen were the standard reference, and distant metastases were identified by periodic computed tomography for 2 years or more after surgery. A logistic regression model was applied to analyze risk factors for lymph node metastases and a Cox regression model for distant metastases. In predicting lymph node metastases, univariate analysis demonstrated significance for all predictors except venous invasion by HE staining. Multivariate analysis showed that venous invasion by EVG and tumor budding by HE showed significance as predictors. In predicting distant metastases, univariate analysis showed significance for lymphatic invasion shown by D2-40, tumor budding shown by CAM5.2 and HE, and lymph node metastases. Multivariate analysis showed only venous invasion by EVG stain as being significantly associated with distant metastases (P=0.001). In conclusion, venous invasion evaluated shown by EVG staining is a useful pathologic predictor for metastases in T1 stage colorectal cancer.