[Bromocriptine in chemotherapy-resistant, metastatic breast cancer. Results of the GO-MC-BROMO 2/82 AIO Study].

In a case report a patient with metastatic breast cancer, who had chemotherapy resistance and hyperprolactinemia, showed a tumor remission following suppression of elevated prolactin levels with bromocriptine. Based on this observation, 18 patients with progressive metastatic breast cancer, chemotherapy resistance and hyperprolactinemia were treated with 10 mg bromocriptine/day in a prospective study. This treatment was in addition to chemotherapy, which was continued for 8 weeks in spite of progressive disease. In all patients, elevated prolactin levels (arithmetic mean 1388 +/- 201 mU/l before treatment) were suppressed to values under 100 mU/l. A partial remission was observed in one single patient which was not clearly attributed to suppression of plasma prolactin levels, but to delayed tumor remission. Side effects, mainly gastrointestinal disorders, were observed in all patients during therapy. In 6/18 patients treatment had to be stopped before end of study due to intolerable nausea and vomiting. It is concluded that suppression of elevated prolactin levels in progressive metastatic breast cancer patients is not effective in restoring tumor sensitivity to chemotherapy.