HISTOLOGIC FEATURES AND CLINICAL-SIGNIFICANCE OF VENOUS INVASION IN COLORECTAL-CARCINOMA WITH HEPATIC METASTASIS

BACKGROUND. In colorectal carcinoma, venous invasion has been related to patient survival. Liver metastasis develops more frequently when ve nous invasion is present. However, the histologic features and clinica l significance of venous invasion are not well understood. METHODS. A histologic study of venous invasion in colorectal carcinoma was perfor med on 19 patients with synchronous hepatic metastasis (Group A), 16 p atients with metachronous hepatic metastasis (Group B), and 26 patient s with Dukes Stage C tumors who survived for 5 years without recurrenc e (Group C). The histologic features of venous invasion were classifie d into three types: tumor cells that were distant from the vein walls were categorized as floating type, those filling the lumen of a vein a s filling type, and those surrounded by a vein obliterated with inflam matory reaction as occlusive type. RESULTS. Venous invasion was presen t in 89.5% of Group A patients and 75% of Group B patients, which was significantly higher than the 15.4% observed in Group C patients (P < 0.001). A slight to extensive degree of venous invasion was found in G roups A and B, but no extensive venous invasion was found in Group C. All patients in Groups A and B (except one patient) had floating, fill ing, or a combination of floating and filling types of venous invasion , whereas all patients in Group C had the occlusive type of venous inv asion. A majority of the patients in all three groups showed invasion of extramural veins. CONCLUSIONS. There is a close relationship betwee n venous invasion and the development of liver metastasis in patients With colorectal carcinoma. Patients With no sign of metastasis had a l ower incidence and lower extent of venous invasion, and inflammatory d amage to the vein walls around the intravenous tumor appeared to reduc e the likelihood of distant metastasis. (C) 1996 American Cancer Socie ty.