Luteinizing hormone releasing hormone (LHRH) agonist therapy for advanced prostate cancer can manifest significant side effects affecting quality of life, most notably hot flashes. This study evaluated the effectiveness of parenteral medroxyprogesterone acetate (MPA) in reducing the frequency and severity of these hot flashes.

A multi-institutional retrospective review of hot flashes from LHRH therapy for prostate cancer was conducted. The hot flashes were quantified and the severity was graded (3-point analogue scale) before and after treatment with MPA. Two doses of MPA (400 or 150 mg intramuscularly) were administered. Statistical analysis (Student's t test) evaluated the quantity of hot flashes, the quality of hot flashes, and dose effectiveness.

A total of 48 men (40 at 400 mg, 8 at 150 mg) with a mean age of 71.4 years (range 54 to 87) from 3 institutions were evaluated. There were 91% with symptomatic improvement with MPA, and half (46%) had a complete response defined as total elimination of hot flashes. The median number of the hot flashes per day decreased from 4 to 1 and the median severity score decreased from 2 to 1 (p <0.05). Significance was not achieved comparing the 2 doses. Complete responders were not noted with the 150 mg dose. Anticipated response to MPA did not correlate with the number or severity of the hot flashes.

This study is the first multi-institutional evaluation of hot flashes demonstrating significant reduction in quantity and severity with MPA. Based on these data we now manage hot flashes associated with LHRH analogues with 400 mg of MPA.