Prostate Cancer Active Surveillance Does Not Up Metastasis Risk
Study finds no difference in metastasis-free survival observed after 15 years compared with radiation therapy or radical prostatectomy.
Active surveillance (AS) for low-risk prostate cancer (PCa) is not associated with a higher rate of metastatic disease after 15 years of follow-up, a finding that contrasts with that of the recently published ProtecT trial, researchers reported at the 2017 congress of the European Association of Urology in London.
In a non-randomized study, a team led by Monique J. Roobol, PhD, MSc, of the Erasmus University Medical Center in Rotterdam, the Netherlands, analyzed data from men diagnosed with localized PCa at the 1st and 2nd screening round of European Randomised Study ofa Screening for Prostate Cancer (ERSPC) Rotterdam (1993–2003) considered suitable for AS (Gleason score 6 or less and stage T2a or less). Of these, 223 men were placed on AS, 312 underwent radiation therapy (RT), and 365 underwent radical prostatectomy (RP). Dr Roobol's group found no statistically significant difference among the groups with respect to the 15-year rate of metastasis-free survival (96.9%, 96.6% and 97.9% for the AS, RT, and RP patients, respectively) and PCa-specific death (97.2%, 97.5%, and 98.5%, respectively).
In the ProtecT (Prostate Testing for Cancer and Treatment) trial, which was published last year in The New England Journal of Medicine (2016;375:1415-1424), Freddie C. Hamdy, MD, of the University of Oxford in the U.K., and colleagues found that men with clinically localized PCa who were randomly assigned to receive AS had a higher rate of metastases (6.3 events per 1000 person-years) compared with men who underwent RP (2.4 events per 1000 person-years) and RT (3.0 per 1000 person-years) after a median follow-up of 10 years. The 3 groups showed no statistically significant difference in survival.
In an interview with Renal & Urology News, Dr Roobol acknowledged that, unlike the ProtecT trial, the study by her and her colleagues was not randomized, which is a study limitation.
She pointed out that in the ProtecT trial, the AS group included not only patients with low-risk PCa, but also patients with intermediate- and high-risk PCa, who would most likely not be considered for AS in clinical practice. In addition, she noted, the active monitoring algorithm used in the study “is in no way comparable with contemporary AS protocols, where at regular intervals rectal exams and biopsies are used to note potential progression of disease.”
In the ProtecT trial, serum PSA levels were measured every 3 months in the first year and every 6 to 12 months thereafter. Investigators assessed changes in PSA levels, and an increase of at least 50% during the previous 12 months triggered a review, according to the NEJM report.
1. Verbeek JFM, Bangma CH, Drost FJH, Roobol MJ. Metastases and death after 15 year of follow-up in men with screened-detected low-risk prostate cancer treated with protocol based active surveillance, radical prostatectomy or radiotherapy. Presented at the 2017 congress of the European Association of Urology in London. Poster 804.