ORLANDO, FL USA (UroToday.com) - Concerns regarding potential over-diagnosis and over-treatment of low-risk prostate cancer have been raised in recent years. Concomitant with research in this area, long-term evaluation of active surveillance for low-risk cancers is needed to inform safe decision-making and development of suitable decision algorithms. In his presentation, Dr. Laurence Klotz provided the third formal analysis of this cohort that began in 1995 as a prospective trial.
Since their last update in 2010, this cohort has grown to 840 men who were diagnosed with low- to intermediate-risk prostate cancer and received histopathological confirmation of adenocarcinoma within 12 months after enrollment. None of them received treatment prior to study entry, and each selected active surveillance to manage their disease. "Intervention was offered for those patients with a PSA doubling time of < 3 years, Gleason score progression (to 4+3 or greater), or unequivocal clinical progression." Their primary outcome measures included "overall and disease-specific survival, rate of treatment, and PSA failure rate in the treated patients."
They found that at the time of analysis, 17.5% of patients had died and 82.5% of patients were alive. A total of 14 (1.7%) deaths were due to prostate cancer and the 20-year actuarial cancer-specific survival was determined to be 86.3%. The cohort includes 206 men followed for 10 or more years and 60 men who have been followed for over 15 years. The number of patients who remain on active surveillance declined over time with 77.1%, 63.4%, 52.3%, and 52.3% of patients remaining after 5, 10, 15, and 20 years, respectively. They determined a hazard ratio in their cohort of non-prostate to prostate cancer mortality of 9.7:1.
This long-term study provides important data showing the safety of active surveillance in the long term. Even over this long-term, patients were 9.7 times more likely to die from other causes than from prostate cancer, 2.7% of patients developed metastatic disease, and 1.5% died from prostate cancer. It will be interesting to see results of a detailed analysis of the subgroups, including those whose cancers were upgraded after repeat biopsies.
Presented by Laurence Klotz, MD, FRCS(C) at the American Urological Association (AUA) Annual Meeting - May 16 - 21, 2014 - Orlando, Florida USA
Sunnybrook Health Sciences Centre, Toronto, ON Canada
Written by Martin Hofmann, MD, University of California (Irvine), and medical writer for UroToday.com