Effects of Intermittent Androgen Suppression in the Treatment of Prostate Cancer: Cycling Changes and Characteristics

Kim, Jung Hyun; Park, Choal Hee; Kim, Chun Il

Abstract

PURPOSE
The purpose of this study was to evaluate cycling change and characteristics of treatment in patients receiving intermittent androgen suppression (IAS).
MATERIALS AND METHODS
From May 1995 to April 2001, we retrospectively reviewed 28 cases of prostate cancer patients treated with IAS. Treatment was initiated with goserelin acetate with flutamide and continued until serum PSA nadir was observed. Medication was then withheld till the serum PSA increased to a predetermined level. This cycle of treatment and no-treatment was repeated until the regulation of PSA became androgen independent.
RESULTS
Patients have completed at least one, and up to four treatment cycles. Mean nadir serum PSA level was 0.69ng/ml, 0.70ng/ml, 1.15ng/ml, 2.64ng/ml for each cycle, and was reached within average 4.7 (2-8) months after beginning treatment. Patients spent an average of 42% of the time not receiving therapy, but the time off therapy decreased as the number of treatment cycles increased. In most cases, side effects related with androgen suppression was improved during off-treatment.
CONCLUSIONS
IAS appears to be a possible treatment option in patients with prostate cancer. This approach could result in reduced toxicity and cost of treatment and affords an improved quality of life when the patient is off therapy.