Changes in Prostate Cancer Grade on Serial Biopsy in Men Undergoing Active Surveillance

Abstract

A B S T R A C T PurposeActive surveillance is now considered a viable treatment option for men with low-risk prostate cancer. However, little is known regarding changes in Gleason grade on serial biopsies over an extended period of time. Patients and MethodsMen diagnosed with prostate cancer between 1998 and 2009 who elected active surveillance as initial treatment, with 6 or more months of follow-up and a minimum of six cores at biopsy, were included in analysis. Upgrading and downgrading were defined as an increase or decrease in primary or secondary Gleason score. Means and frequency tables were used to describe patient characteristics, and treatment-free survival rates were determined by life-table product limit estimates. ResultsThree hundred seventy-seven men met inclusion criteria. Mean age at diagnosis was 61.9 years. Fifty-three percent of men had prostate-specific antigen of 6 ng/mL or less, and 94% had Gleason score of 6 or less. A majority of men were cT1 (62%), had less than 33% of biopsy cores involved (80%), and were low risk (77%) at diagnosis. Median number of cores taken at diagnostic biopsy was 13, mean time to follow-up was 18.5 months, and 29% of men had three or more repeat biopsies. Overall, 34% (129 men) were found to have an increase in Gleason grade. The majority of men who experienced an upgrade (81%) did so by their second repeat biopsy. ConclusionA proportion of men experience an upgrade in Gleason score while undergoing active surveillance. Men who experience early upgrading likely represent initial sampling error, whereas later upgrading may reflect tumor dedifferentiation.

Active Surveillance for Prostate Cancer: A Systematic Review of the Literature

“…Serial prostate biopsy serves to identify both 0 1 2 ) 9 7 6 -9 8 3 situations, with the early ''confirmatory'' biopsy aimed at minimizing the risk of undersampling. Table 3 displays the pathologic outcomes after the first repeat biopsy from the series identified [34][35][36]. Investigators from Memorial Sloan-Kettering Cancer Center used a strategy of early (within 3 mo) confirmatory biopsy in a cohort of men on AS [13].…”

“…PRIAS recommends prostate biopsy at 1, 4, and 7 yr, while men from the Johns Hopkins group are followed with yearly biopsies. With a median follow-up of 54 mo after diagnostic biopsy, University of California, San Francisco (UCSF) investigators described the results of multiple surveillance biopsies over time [34]. The risk of grade progression with subsequent surveillance biopsies ranged from 22% to 30% with each biopsy round, with the majority of upgrades being to Gleason 3 + 4 disease.…”

An assessment of Prostate Cancer Research International: Active Surveillance (PRIAS) criteria for active surveillance of clinically low-risk prostate cancer patients

“…In addition, prostate magnetic resonance imaging and other diagnostic tests may be used to decrease the risk of misclassification. [30][31][32][33] Furthermore, the estimates in this study were derived from a prostatectomy cohort. It is possible that there are other factors, such as rate of PSA change or proportion of cancer, that may influence a patient's treatment selection.…”

Five-year follow-up of active surveillance for prostate cancer: A Canadian community-based urological experience

“…6 Early upgrading following repeat biopsy is concerning for initial sampling error, whereas later upgrading may represent true dedifferentiation of prostate cancer. 11 To increase the precision of risk assignment, most centres now recommend a confirmatory biopsy or an extended-template biopsy before initiating AS. 12 Unfortunately, due to the retrospective nature of this study most patients did not receive a confirmatory biopsy.…”