Objective: To evaluate systematically interrupted androgen suppression (SIAS) 6 mo a year compared with continuous androgen suppression (CAS) in prostate cancer treatment.
Patients and methods: All patients underwent maximal androgen blockade for 6 mo. Then, depending on the randomisation arm, they continued (CAS) or stopped their treatment for 6 mo before they resumed it a year later and so on (SIAS). Primary end points were patient's health-related quality of life (HQOL) and time to progression. Secondary end points were cancer-specific and overall survival. Progression was defined by a clinical event or PSA value exceeding double the value obtained at the end of the first 6 mo of therapy.
Results: Sixty-two patients were randomised to CAS and 67 to SIAS. There were no significant differences between groups at baseline. Androgen suppression was associated with HQOL deterioration except for an improvement in urinary symptoms. The 6-mo off-therapy period was not long enough to regain normal testosterone values. There was no difference in HQOL scores between CAS and SIAS except that men in the latter group reported a greater need for painkillers but a better ability to have an erection. Progression occurred in 62 patients (48.1%) with no significant difference between CAS and SIAS with a mean follow-up of 44.8 mo. Death occurred in 41 patients and specific death in 19 patients (10% and 19% of the CAS and SIAS groups, respectively).
Conclusions: Although patients in the SIAS group were maintained off-therapy 50% of the time, insufficient testosterone recovery in this group likely explains why differences between the two groups were moderate or absent with regards to HQOL and survival, respectively.