Medroxyprogesterone acetate treatment reduces serum interleukin-6 levels in patients with metastatic breast carcinoma

Abstract

The serum interleukin (IL)-6 concentration was very low in patients with metastatic breast carcinoma who had received oral medroxyprogesterone acetate (MPA) treatment as compared with those who had not. Accordingly, the authors conducted a prospective study to determine whether MPA treatment reduces the serum level of IL-6 in patients with this disease. In 21 consecutive Japanese patients who were scheduled to receive oral MPA treatment at doses of 600, 800 or 1200 mg/day, serum concentrations of IL-6 were determined with a sensitive enzyme-immunoassay prior to the administration of MPA and again at 4 weeks after the treatment was started. In addition, plasma levels of MPA were determined by high-performance liquid chromatography (HPLC). Four weeks after the oral MPA therapy was started, serum IL-6 levels decreased in all 21 patients regardless of whether or not they responded to the treatment. Although the extent of decrease in the serum IL-6 (delta IL-6) did not correlate with the daily dose of MPA, it correlated closely with the plasma MPA level in these patients. Subjective improvement in appetite and weight gain were more frequent in the delta IL-6 > 3 pg/mL group compared with the delta IL-6 < or = 3 pg/mL group (80% vs. 45% and 70% vs. 45%, respectively). Similar results were obtained for improvement in patients' sense of well-being (100% vs. 55%). Oral MPA treatment reduces serum IL-6 concentration in patients with metastatic breast carcinoma, but the decrease is not associated with response to MPA. This observation may indicate a potential of this agent for producing subjective improvement.