Flow cytometric analysis of tumor antigen TA-4 in cervical cytologic specimens.

Flow cytometric analysis of cellular contents of TA-4, a tumor antigen of squamous cell carcinoma, was performed in vaginal smears from 143 women. Abnormal findings, characterized by a cell peak with high fluorescence intensity, appeared in 85.7% of cases (54/63) of cervical squamous cell carcinoma, 80% of cases (4/5) of severe dysplasia, 42.9% of cases (3/7) of mild-to-moderate dysplasia, and in 20.6% of cases of healthy women (13/63). Cellular compositions sorted from abnormal cell fractions with high fluorescence intensity consisted, not only of malignant cells but also of morphologically nonmalignant cells. Immunohistochemical studies indicated that these nonmalignant cells with high TA-4 content originated from the intermediate layer of squamous epithelium adjacent to the cancer nest. These findings indicate that this method may be a useful approach for investigating some biologic characteristics of cells and for detecting cervical cancer or its precursors.