Use of monoclonal antibody for assessment of estrogen and progesterone receptors in malignant effusions.

An immunocytochemical assay utilizing specific monoclonal antibodies against estrogen receptor (ER) and progesterone receptor (PgR) has been shown to be highly reliable for the detection of hormone receptors in hormone sensitive tumors. To assess the usefulness of this technique in malignant effusions, CytospinR (Shandon, Inc., Pittsburgh, PA 15275), preparations of 41 pleural and ascitic fluid were studied. The findings from the malignant cells employing estrogen and progesterone receptor immunocytochemical assay were compared with the results obtained from primary tumors by biochemical (dextran-coated charcoal) assay. The results agreed in 88% for ER and 83% for PgR. This study supports the potential value of cytochemical technique in detection of hormone receptors in malignant effusions. Assessment of hormone receptors in malignant effusions may be of clinical significance, particularly in situations where the hormone receptor status of the original tumor is not known. This information may also have some diagnostic and therapeutic importance in assessment of patients presenting with metastatic tumors of unknown origin.