Development of liver metastasis in colorectal carcinoma. With special reference to venous invasion and basement membrane laminin.

The development of hepatic metastases in 344 patients with colorectal carcinoma was examined for correlation with the presence of both venous invasion by the primary tumor and basement membranes in the tumor tissue. The former was detected by Victoria blue and hematoxylin-eosin staining and the latter by antilaminin antibody. A significant difference in the incidence of venous invasion was noted between patients with and those without liver metastasis at surgery. Basement membrane deposition was found in half of all cases of well differentiated adenocarcinoma, which was significantly high compared with other tumor types. This was more distinct in metastatic foci in the liver and lymph nodes than in the primary lesion, but less marked in intravascular tumor tissue. Basement membrane deposition was seen more frequently in Dukes' A tumors than in B tumors, although this was not statistically significant. No relationship was found between basement membrane laminin positivity and five-year survival, nor was there any correlation between the incidence of liver metastasis and tumor histologic type. Venous invasion was considered to be intimately related to the development of liver metastasis. Deposition of laminin-positive basement membrane was dependent on the grade of tumor differentiation, whereas it had no direct relation to the development of liver metastasis.