ORLANDO, FL USA (UroToday.com) - In the REDEEM trial, men with very low risk prostate cancer were randomized to dutasteride 0.5mg/day or placebo and underwent 12-core biopsy at 1.5 and 3 years. The primary endpoint in this study was pathologic or therapeutic progression. Pathologic progression was defined as an increase in Gleason score to 7 or greater, 4 or more cores involved with cancer or >50% of any core occupied with cancer. Therapeutic progression was defined as active intervention such as radical prostatectomy, radiotherapy, or androgen deprivation therapy. This was a multi-center trial in Canada and the US. Inclusion criteria were entry PSA <11ng/ml, Gleason score 6 or less, 3 or fewer cores involved with prostate cancer and <50% of each core containing cancer.
Average PSA at entry was about 5.7ng/ml in both arms. 96% of participants completed the study. The time to cancer progression was improved at 1.5 and 4 years with a relative risk reduction of 38.9%. More dutasteride treated patients had no cancer detectable in the final biopsy compared with placebo patients; no cancer was detected in the final biopsy in 23% of placebo patients and 36% of dutasteride patients. Higher Gleason score was not detected in the dutasteride group. The biopsy characteristics in the final biopsy were similar for Gleason 6 in both arms, and less severity for dutasteride for Gleason 7 and above (progression to Gleason score >7 occurred in 14% of dutasteride and 16% of placebo patients). Patients randomized to dutasteride had significantly reduced anxiety and fear of cancer progression. This may have been due to PSA decline and negative prostate biopsies. Sexual function among sexually active patients was similar between treated and placebo patients. Dr. Fleshner pointed out that this strategy might help keep patients away from unnecessary treatment.
Presented by Neil Fleshner, MD, MPH, FRCSC at the 2011 Genitourinary Cancers Symposium, General Session I: Emerging Trends in the Characterization and Treatment Decisions of Newly Diagnosed Prostate Cancer - February 17-19, 2011 - Orlando World Center Marriott, Orlando, Florida USA