Oral high-dose medroxyprogesterone acetate (MPA) treatment: cortisol/MPA serum profiles in relation to breast cancer regression.
Medroxyprogesterone acetate (MPA), a potent synthetic progestin, has been widely used in the hormonal treatment of advanced breast cancer, but presently with varying dose schedules. The availability of a sensitive RIA-method for determination of serum MPA has stimulated the research on MPA serum levels in patients after repeated MPA administration. The aim of this study was to assay blood level profiles of MPA as well as of cortisol during repeated high-dose orally administered MPA. 34 patients with metastatic breast cancer were enrolled in this study. 12 patients died already within the first 4 weeks of MPA treatment due to multiple metastases. The dosage regimen based on the daily oral administration of 1,000 mg MPA suspension. During MPA treatment, a decrease of cortisol serum levels was observed in nearly all patients. Within the observation time of 8 months out of 22 evaluable cases 18.2% responded to the therapy (complete and partial response). No change was observed in 36.4% and progression in 45.5% of the patients. Within the remission (complete and partial) group, a good correlation between constant MPA serum levels above 150 ng/ml and remission was observed. But in the groups with no change and progression no such correlation could be observed.
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008525:Medroxyprogesterone / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use; D008875:Middle Aged; D011379:Prognosis; D011863:Radioimmunoassay; D013997:Time Factors
D008525:Medroxyprogesterone; D006854:Hydrocortisone