Medical thoracoscopy: hormone receptor content in pleural metastases due to breast cancer

Pleural metastases are common in the course of breast cancer, but, to date, the role of oestrogen receptor (OR) and progesterone receptor (PgR) content in metastatic tissue has been poorly evaluated. A series of 50 consecutive patients with a history of breast cancer (median age 64 yrs, range 40-86 yrs), which presented with pleural effusion and therefore underwent medical thoracoscopy, was analysed. Metastatic pleural involvement was histologically confirmed in all patients. The hormone receptor status of the pleural metastases was investigated using the immunohistochemical method in 49 and the biochemical method in 31 cases. The immunohistochemical test was performed using monoclonal antibodies. Biochemical analysis was performed on specimens quick-frozen in liquid nitrogen. OR and PgR were measured with the dextran-coated charcoal assay and Scatchard analysis. Immunohistochemical analysis yielded 29 OR-positive and 25 PgR-positive cases and biochemical analysis yielded 16 OR-positive and four PgR-positive cases, sometimes discrepant to hormone status of the primary breast cancer. Using a semiquantitative immunoreactive score, there was a significant association between receptor positivity and survival, but only for PgR positivity. Immunohistochemical and biochemical detection of hormone receptors (oestrogen and progesterone) in pleural metastases of breast cancer is feasible based on medical thoracoscopy as the method of choice, by which sufficient specimens may be obtained. The receptor status may enable a decision on antihormonal treatment. Whether a positive receptor status in pleural metastatic tissue is associated with a better prognosis remains to be confirmed.