Prostate cancer treated by anti-androgens: is sexual function preserved?

This paper reports on results of the EORTC protocol 30892, an open, prospec tive, randomized study of 310 patients with previously untreated metastatic prostate cancer with favourable prognostic factors who were treated by eit her flutamide (FLU) or cyproterone acetate (CPA) monotherapy The final anal ysis with regard to the main end points, time to progression and survival a re still pending. Final results related to the evaluation of sexual functio ning prior to and under treatment are reported here. Of 310 randomized pati ents 294 were eligible for evaluation within this side study. The median ag e was 71 years (range 48-85). Potential risk factors related to age, genera l health and prostate cancer were evaluated. For evaluation of sexual funct ions a five-item questionnaire was used which was administered by the inves tigator. The protocol allowed time dependent observations at 3-monthly foll ow-up visits. Sexual functioning was dependent on age but not on prostate c ancer-related parameters. Sexual functions at entry were similar within the two treatment groups, spontaneous (nightly) erections and sexual activity were seen in 43-51% and 29-35% of cases. Under treatment, sexual functions under FLU and CPA declined slowly with median times of 12.9 and 5.8 months versus 13.7 and 8.9 months respectively for spontaneous erections and sexua l activity. Eventually, with an average observation time in excess of 2 yea rs, loss of spontaneous erections and of sexual activity occurred in 80% ve rsus 92% and in 78% versus 88% of men under FLU versus CPA treatment respec tively. None of these differences reached statistical significance. Mainten ance of potency under treatment with FLU as reported in the literature is n ot confirmed in this study. However, loss of sexual functions under monothe rapy with both antiandrogens is slow and 10-20% of men retain sexual activi ty after 2-6 years of treatment. This observation can be exploited in new t reatment schemes and is likely to lead to improved quality of life. The adv antage of FLU in time and total preservation of sexual functions is statist ically not significant and must be balanced against the side effects of FLU and other pure antiandrogens, which may exceed those of CPA especially wit h respect to gynaecomastia. Hepatic toxicity may limit the long-term use of both drugs. (C) 2000 Cancer Research Campaign.