High-Dose Medroxyprogesterone Acetate (MPA) Treatment in Advanced Breast Cancer. A Review

Abstract

Medroxyprogesterone acetate (MPA) when employed at high doses (greater than or equal to 500 greater than or equal to 1000 mg/day i.m.) can produce objective remission with improved survival in about 30% of postmenopausal women with advanced breast cancer resistant to cytotoxic drugs and endocrine therapies. When administered to women not previously treated with chemotherapy, the objective remission response rate reached 40%. From available evidence, high dose MPA can be considered a useful agent in the treatment of advanced breast cancer in postmenopausal women with soft tissue, pulmonary, pleural or osseous involvement even when patients have become refractory to prior hormone and cytotoxic therapies. Early results suggest that the response rate can be increased in patients with estrogen and/or progesterone-positive receptors. It is note worthy that in a study conducted on postmenopausal women resistant to cytotoxic and/or hormonal drugs, the median duration of survival was 13.5 months, while CRs plus PRs did not reach the median at 24 months after starting MPA treatment. High dose MPA is essentially devoid of major side effects. Relief of pain, increase in appetite and body weight, and sense of well being are characteristic features of the improved quality of life under MPA treatment. However, a gluteal abscess (from 2% to 20% dose related) is the most frequent side effect. A promising area for future studies is combined therapy using hormonal and cytotoxic agents or alternating sequential combinations. Well-designed studies are needed to develop means for increasing the complete response rate and therefore survival. Recent studies of combined chemo- and hormonal (MPA) therapy have yielded objective tumor regressions of 53 to 80% with an increased rate of complete remissions and duration of response.

An Analysis of Serum Interleukin-6 Levels to Predict Benefits of Medroxyprogesterone Acetate in Advanced or Recurrent Breast Cancer

“…In addition to a high response rate of approximately 40%, medroxyprogesterone acetate (MPA) treatment as an endocrine therapy is more likely to be effective in ER(–) cases than other endocrine therapeutic agents in recurrent or advanced breast cancer, holding an important position as first- and second-line therapy [1, 2, 3, 4]. Further, the accessory effects of MPA such as appetite stimulation, improvement in performance status (PS) and bone marrow protection are advantageous for many recurrent cases, and may lead to more frequent use of MPA.…”

A Randomized Controlled Comparative Study of Oral Medroxyprogesterone Acetate 1,200 and 600 mg in Patients with Advanced or Recurrent Breast Cancer

“…Enomoto et al [15]reported that the response rate of MPA 1,200 mg was somewhat superior to 600 mg but there were no significant differences between the two doses in combination with cyclophosphamide and epirubicin. Ganzina [16]reported that the response rate in patients treated with MPA at 200 mg or less was 17% and thus concluded that so-called ‘low dose MPA therapy’ cannot achieve a satisfactory response rate. However, ‘high dose MPA therapy’ using higher doses appears to produce no marked difference in the response rate of different doses.…”

Therapeutic Aspects of Low-Risk Breast Cancer

“…Progestin treatment of advanced breast cancer has been thought to be of age for several years [18]. However, recently route of administration and dosage have again been scrutiniz ed and these questions can no longer be regarded as solved [33].…”