EAU 2011 - Phase III study of intermittent MAB vs. continuous MAB - Session Highlights

VIENNA, AUSTRIA (UroToday.com) - The investigators presented long term follow up on use of intermittent hormonal therapy vs. continuous therapy for the treatment of advanced prostate cancer.

Their objective was to determine if intermittent therapy is associated with a shorter survival time.

In the study, a total of 766 patients with locally advanced or metastatic prostate cancer received a three-month induction with androgen deprivation therapy. 626 patients with a PSA decrease below 4 ng/ml or 80% below the initial value were randomized to cyproterone acetate (CPA) 200 mg for two weeks and then monthly depot injections with a LHRH analogue plus 200 mg of CPA daily during induction or intermittent treatment.

A total of 474 patients have died, and 90 were lost to follow up, of which 37 withdrew. Most importantly, there was no difference in survival, with a hazard ratio = 0.96. There were 239 deaths in the intermittent group and 235 in the continuous group. There were more cancer deaths in the intermittent treatment arm (136 vs. 109), more cardiovascular deaths in the continuous arm (68 vs. 62), as well as more deaths from other causes (58 vs. 41). The hazard ratio of a cancer death was 1.27 (p = 0.06) in the intermittent arm compared to the continuous treatment group. For cardiovascular deaths the hazard ratios are 1.05 (p =0.77) for continuous compared to intermittent, and for other deaths the hazard ratio for continuous compared to intermittent is 1.38 (p=0.11). The extended follow up has an additional 135 deaths since the last analysis and exceeds the number of events specified in the original power analysis. The additional 5 years of follow up suggests that the study has accumulated almost 3,000 person years at risk among the 626 randomized patients and the median follow up is now 57 months. These data suggest that intermittent therapy is not associated with a reduction in survival.


Presented by Fernando M. Calais Da Silva Jr., MD, et al. at the 26th Annual European Association of Urology (EAU) Congress - March 18 - 21, 2011 - Austria Centre Vienna, Vienna, Austria


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