Intermittent Androgen Deprivation(IAD) with Cyproterone Acetate Monotherapy for Prostate Cancer: A preliminary report

Shin, Jae Sung; Lee, Hyun Moo; Choi, Han Yong

Abstract

PURPOSE: The purpose of this study was to evaluate the feasibility of using IAD, as a steroidal antiandrogen (cyproterone acetate) monotherapy, for prostate cancer.
MATERIALS AND METHODS
A total of 43 prostate cancer patients (Stage A to C in 27, D1 in 2 and D2 in 14) were reviewed. Androgen deprivation, with cyproterone acetate (200-300mg P.O/day), was continued until a serum prostate specific antigen (PSA) nadir was maintained for at least 3 months. Medication was then discontinued until the serum PSA reached a predetermined level. This cycle of treatment was repeated until there was a continual increase in the PSA irrespective of the medication.
RESULTS
The mean observation period was 10.5 months, ranging from 4 to 28 months. In seven of the 43 patients, there was treatment failure before entering the off-treatment period of the 1st cycle. 17 of the remaining 36 patients completed the on-treatment during cycle 1, with a median time to PSA nadir of 4 months. Seven patients completed cycle 1, with a median time off-treatment of 5 months (43% of the treatment cycle). Nineteen patients are still in the on-treatment intervals and 10 in the off-treatment intervals of their first cycles. Two patients completed the on-treatment of the 2nd cycle, with a median time to PSA nadir of 2.5 months. During the off-treatment interval, most patients reported an improvement in the symptoms associated with androgen suppression.
CONCLUSIONS
IAD, using cyproterone acetate monotherapy, is a feasible alternative for continuous androgen deprivation in the treatment of prostate cancer. It also results in the reduction of toxicity, cost of treatment and possibly a delay in the tumor progression.