Biennial prostate biopsies appear to be an acceptable alternative to annual biopsies for men on active surveillance (AS) for low-risk prostate cancer (PCa), investigators concluded.
On average, biennial biopsies beginning at AS enrollment will detect cancer upgrading only 6 to 8 months later than annual biopsies, “a delay that is unlikely to substantially increase risk for adverse downstream outcomes on the basis of our assessment and published studies of treatment delays in low- to moderate-risk patients,” Lurdes Y.T. Inoue, PhD, of the University of Washington in Seattle, and colleagues reported in a paper published online ahead of print in Annals of Internal Medicine. Biennial biopsies starting after the first confirmatory biopsy at 1 year after enrollment delayed detection of upgrading by an average of only 3 to 5 months.
Noting a lack of consensus about how to implement AS for this patient population, Dr Inoue’s group compared the risks of upgrading from a Gleason score of 6 or less to 7 or more across AS cohorts at Johns Hopkins University in Baltimore, Canary Prostate Active Surveillance Study, University of California San Francisco, and the University of Toronto. The investigators analyzed individual-level data from 2576 men aged 40 to 80 years with a Gleason score of 2 to 6 and clinical stage T1 or T2 PCa enrolled from 1995 to 2014.
“Men in the different AS cohorts have different risks for biopsy upgrading after variable surveillance protocols and competing treatments are accounted for,” the authors concluded. “Despite these differences, the consequences of more versus less frequent biopsies seem to be similar across cohorts.”
A key limitation of the study, the investigators acknowledged, was that they considered only biopsy upgrading instead of true pathologic upgrading.
Inoue LYT, Lin DW, Newcomb LF, et al. Comparative analysis of biopsy upgrading in four prostate cancer active surveillance cohorts. Ann Intern Med 2017; published online ahead of print. doi: 10.7326/M17-0548