Biochemical markers in the plasma and tumors of patients with gynecologic malignancies.

Tumor markers in gynecologic malignancies can be classified generally as oncofetal proteins, carcino-placental proteins, and more specific tumor-associated antigens. Carcinoembryonic antigen (CEA) is most effective as a tumor marker in mucinous adenocarcinomas of the endocervix and ovary and in keratinizing squamous cell carcinomas of the cervix. In contrast, the use of alphafetoprotein (AFP) in gynecologic cancer is limited to patients with germ cell tumors of the ovary and specifically endodermal sinus tumors. The beta subunit of human chorionic gonadotropin (beta-hCG) remains an exemplary tumor marker for trophoblastic malignancies and may be useful in selected patients with epithelial carcinomas of the ovary. Plasma levels of these antigens are generally related to total tumor burden (tumor antigen concentration x extent of disease)). Although the lack of specificity of these markers has limited their use in the diagnosis of gynecologic malignancies, they have been effective as a means of monitoring disease status in patients whose tumors contain high antigen concentrations. More specific tumor-associated antigens have been described in ovarian cervical cancers, but their clinical efficacy remains to be demonstrated in large numbers of patients. Immunohistochemical staining of tissue specimens identifies patients whose tumors contain high antigen concentrations and who therefore should benefit most from serial plasma determinations following therapy. Potential future uses of biochemical markers include radioimmunodetection procedures using radiolabelled antibodies to tumor-associated antigens and antigen-directed chemotherapy.