The present study was performed to determine the preoperative response rates of eight different tumor markers in patients with preoperative diagnosis of gynecological carcinomas including breast cancer, and to determine by follow-up studies changes of serum levels of these markers in patients after primary operative treatment. In 457 patients with gynecological malignancies the following markers were determined: sialic acid transferase, carcinoembryonic antigen, tissue polypeptide antigen, alpha-1-antitrypsin, alpha-2-macroglobulin, C-reactive protein, pregnancy-specific beta-1-glycoprotein, pregnancy-associated alpha-2-glycoprotein. The different markers were determined simultaneously. Serving as controls were 439 patients with benign gynecological disorders. The validity of each single marker in comparison to the others was analyzed by statistical methods. For the purpose of preoperative diagnosis of gynecological carcinomas none of these eight markers gave satisfactory results. Followup studies demonstrated that changes in the serum levels of these markers correlated with the course of the disease and actually showed a "lead time" over clinical diagnosis. The simultaneous evaluation of the different markers was clearly superior in comparison with any single marker determination.