Background
Androgen deprivation therapy (ADT) is a common treatment for specific types and phases of prostate cancer. The side effects of ADT include deteriorating sexual function and quality of life.
Recent attention has therefore focused on intermittent ADT treatment to minimise side effects.
Aim
To investigate the effects of testosterone change on the sexual function of men with prostate cancer undergoing intermittent maximal androgen deprivation therapy.
Methods
Data came from a phase II cohort study of 250 Australian patients (34% aged <70, 52% 70-79 and 14% 80+) with prostate cancer undergoing intermittent maximal androgen deprivation therapy.
Flutamide (Eulexin®) 250 mg 3 times daily and leuprolide (Lucrin®) 22.5 mg were given during a nine-month treatment phase (ONPhase). Therapy was ceased provided that prostate specific antigen (PSA) was 4 ng/ml or less.
Monitoring continued every three months for a further two years (OFFPhase) unless re-treatment occurred. Sexual function was assessed with the QLQ-PR25 version 3.0 prostate module in conjunction with the QLQ-C30 questionnaire at baseline and every three months thereafter.
Results
Baseline mean testosterone level was 14.7ng/ml. At three months into ADT, 98% men achieved castrate levels (<2ng/ml).
Median time to recover to eugonadal testosterone of 10ng/ml was 10.4 months, with 30% of men not reaching this level two years after completing ADT. At baseline 46% of patients reported sexual activity with almost half (43%) reporting mild or no erectile problems.
Sixty-three per cent of the men reported an interest in sex (libido) at baseline, with 28% reporting moderate to high libido. In addition, 26% felt less masculine as a result of illness or treatment.
By three months of ONPhase all parameters deteriorated, worsening to a low at nine months. Only 13% of the men reported sexual activity and 10% reported moderate to high libido.
The proportion of men feeling less masculine increased to 50%. During the OFFPhase recovery was observed. Of those previously sexually active men 52% resumed sexual activity.
Of these patients, all reported erectile function returning to baseline. Levels of libido, masculinity and sexual activity recovered but not to baseline levels.
Conclusion
Libido, sexual activity and perceptions of masculinity deteriorate during ONPhase. Of the sexually active men at baseline half will resume sexual activity despite nine months of androgen deprivation therapy.
A subgroup of men (about one in five of those sexually active at baseline) appear to maintain sexual activity despite testosterone suppression.
