Tumor growth and metastasis increases the serum concentration of basement membrane proteins.

Serum concentrations of two basement membrane proteins, laminin and collagen type IV, were studied in three spontaneously metastasising experimental tumors: 3LL Lewis Lung and B16 melanoma of the mouse and R3230 adenocarcinoma of the rat. In the Lewis Lung tumor the mass of the primary tumor or the degree of metastasis correlated well with the concentration of serum laminin. In B16 melanoma the level of serum laminin was only significantly raised when the tumor had metastasised to the lung. No correlation between tumor mass and serum laminin was found in the R3230 adenocarcinoma. The serum concentrations of collagen IV, however, were raised to a certain extent during primary tumor growth and metastasis. Immunofluorescent staining for laminin in the Lewis Lung tumor demonstrated positive reactions in the primary tumor and in metastases of the lung. The data indicate the possibility of using similar tests for clinical tumor diagnosis.