Delaying ADT for PSA-Only Relapse May Be Viable Option for Men with Prostate Cancer and PSA-Only Relapses
Chicago, IL—Delaying androgen deprivation therapy (ADT) for at least 2 years did not lead to worse overall survival or prostate cancer–specific survival compared with the initiation of ADT within 3 months of rising prostate-specific antigen (PSA) in men with PSA-only relapse (ie, biochemical relapse) after the primary treatment of prostate cancer with surgery or radiation, according to the results of a large population-based study presented at the 2014 American Society of Clinical Oncology (ASCO) meeting and highlighted at a press briefing.
Commenting on the study, ASCO President Clifford A. Hudis, MD, Chief, Breast Cancer Medicine Service, Memorial Sloan Kettering Cancer Center, New York, said, “This study may provide reassurance about deferring ADT for quality-of-life reasons. We can tell patients that they don’t have to rush to treatment, and the results provide reassurance for us about withholding ADT.”
Lead investigator Xabier Garcia-de-Albeniz, MD, ScM, Research Associate, Harvard University School of Public Health, Boston, said, “Immediate versus deferred ADT for men with a PSA-only recurrence is a grey area.” He noted that the National Comprehensive Cancer Network guidelines say that the role of ADT in this setting is a “therapeutic dilemma,” noting that “These findings suggest that there may be no need to rush to ADT. Obviously, this is an observational study with several limitations. A large ongoing randomized phase 3 trial is looking at this question and results of that trial will answer the question and serve as the gold standard.”
The study was based on data for more than 14,000 patients participating in the prospective Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry based at the University of California, San Francisco. Overall, 2022 men had a PSA-only relapse (defined as >.02 ng/mL or 3 rising PSA levels, asymptomatic, or no metastasis) after curative surgery or radiation.
Patients with a PSA-only relapse received immediate ADT (ie, within 3 months of rising PSA) or deferred ADT (ie, at least 2 years after PSA relapse, or for metastasis, symptoms, or short PSA doubling time).
The median time from primary treatment to PSA relapse was 27 months. The median follow-up after PSA relapse was 41 months. The median age of the patients was 69 years (range, 63-74 years), 33.8% of the patients had a Gleason score of >7, and 31.8% received radiation as primary treatment.
During follow-up, 176 deaths were reported; 37 of these deaths were from prostate cancer.
The 5-year survival rates were 85.1% for the deferred ADT group and 87.2% for immediate ADT. The 10-year survival rate was identical in both groups, at 71.6%.
Person-months were used as the unit for analysis (instead of persons); 84,716 person-months were assigned to deferred ADT, and 13,889 person-months were assigned for the immediate ADT strategy.
Dr Garcia-de-Albeniz and other experts said that these results could be included in discussions with patients who had a PSA-only relapse who may want to delay ADT because of unwanted side effects or other reasons.