ATHENSIn patients with advanced or inoperable prostate cancer, intermittent androgen suppression shows promise as an equally effective, less toxic, and cheaper alternative to continuous hormone blockade, Dr. Sergio Bracarda, of Perugia University (Italy), said at the 23rd Congress of the European Society for Medical Oncology (ESMO).
In an attempt to determine whether discontinuous treatment could avoid or delay the emergence of hormone-refractory disease, Dr. Bracarda and his colleagues used prostate-specific antigen (PSA) measurements to guide the stopping and re-starting of androgen ablation therapy.
They treated 88 consecutive patients with either a luteinizing hormone releasing hormone (LHRH) analog plus a peripheral antiandrogen (complete androgen blockade) or with an LHRH analog alone and only 1 month of an antiandrogen to prevent flare-ups (partial androgen blockade). Hormonal blockade was interrupted when a patients PSA level fell to zero and was resumed when the PSA level approached 10 ng/mL.
In his discussion of the results obtained on 73 of these patients, Dr. Bracarda said that no instances of disease progression to a hormone-refractory status have been observed during a median follow-up of 29 months. In contrast, he noted, historical data suggest that virtually all patients receiving continuous androgen suppression develop resistance within 6 to 18 months.
Resumption of sexual activity was reported by 88.6% of patients during the off-therapy period of the first cycle (mean duration, 6 months); by 68% of patients during the second off-therapy period (mean duration, 3 months); and by 80% during the third drug hiatus. Overall, study participants were able to spend more than half of the follow-up period off therapy.
Cost savings were achieved with intermittent androgen suppression, compared with continuous suppression. The cost of therapy averaged about $2,300 per year with complete androgen blockade and about $1,200 per year with partial androgen blockade.