CA 125 as an indicator of pleural metastases in breast cancer patients

In this study we analyzed the role of CA 125 serum levels in the diagnosis and follow-up of pleural metastases in breast cancer patients. CA 125 serum levels were measured in patients with lung and/or pleural metastases: a) at the time of detection of the metastases, b) 3 months thereafter during therapy and c) before and after drainage of pleural effusions. In all patients occurrence of metastases at other localisations was excluded. For CA 125 measurements ELISA sandwich assays were performed. In 76 patients with metastases CA 125 levels were elevated in 8% of patients with lung metastases, in 89% with pleural metastases and in 94% with-both sites of metastases. In patients with lung metastases, the CA 125 concentrations did not follow the clinical course of disease, while in patients with pleural metastases CA 125 levels followed the course of disease in 25 of 25 progressions and in 5 of 6 remissions. After the puncture of pleural effusions CA 125 levels decreased in 7 of 14 patients and remained stable in the other 7 patients.