Gamma fetal antigen in spontaneous and carcinogen-induced rodent tumors. Survey of sarcomas and hepatic carcinomas.

Fourteen distinct rodent sarcomas and hepatic carcinomas were examined serologically for the presence of the tumor-associated gamma fetal antigen (gamma-FA). Using heterologous antiserum specific for gamma-FA, this antigen could be identified in saline extracts of each of the tumors surveyed; animals bearing gamma-FA-positive cancers had immunoprecipitable levels of gamma-FA in their sera. Although gamma-FA was associated with hepatic neoplasms of diverse phenotypes, low- or non-albumin-producing tumors had more gamma-FA per milligram of saline-extractable protein than did the more differentiated hepatocellular carcinomas. Gamma-FA became detectable in the sera of BALB/c mice bearing transplanted Meth A sarcomas and hepatocarcinogen-treated Wistar rats early during the time course of tumor growth. These data strongly suggest that serum gamma-FA levels may serve as a useful monitor of tumor presence and progression.