Estrogen and progesterone receptors in neoplastic cells of metastatic pleural effusion of breast carcinoma before and after tamoxifen therapy. Correlation with the clinical response.

We have investigated the activity of tamoxifen in 12 post-menopause patients affected by advanced breast carcinoma and, in this specific case, by metastatic pleural effusion. A receptor assay was carried out on all patients to assess the estrogen and progesterone receptor activity in pleural effusion tumor cells, cytologically confirmed. The assay was performed both at the moment of the diagnostic check and after a week of 30 mg/die of tamoxifen therapy. We obtained a temporary reduction of the pleural effusion in 5 patients out of 12 (42%). Four out of these 5 patients presented estrogen receptors (ER+) at the first assay. In the 4 patients with negative receptors (ER-) neither a decrease of the percentage of tumoral cells, nor a reduction of the effusion was ascertained. This study shows that also for pleural effusions tamoxifen's therapeutic benefit was obtainable only in those patients with estrogen receptors in the tumoral cells.