Risk of Gleason Grade Inaccuracies in Prostate Cancer Patients Eligible for Active Surveillance

ObjectiveTo evaluate increases in Gleason grade because of sample bias after immediate rebiopsy or prostatectomy for patients considered active surveillance candidates by institutional protocol.MethodsA contemporary medical literature search was performed using PubMed. Series were included if the patients had no more than Gleason 6 prostate cancer score on initial biopsy and underwent a prostatectomy or rebiopsy within 6 months. Patient sets using neoadjuvant hormonal therapy or focal prostate treatment were excluded.ResultsIn patients who would have fallen into the D'Amico low-risk prostate cancer group, 42% were found to have an increase in the Gleason score: 32% resulting in grade ≥7 disease and 3% grade ≥8. For series that limited patients to the Epstein criteria, Gleason upgrades were 34%, 29%, and 2%, respectively. Of the 139 patients whose second tissue specimens were from a rebiopsy, 17% were found to have grade ≥7 disease, whereas only 1 patient had grade ≥8. There were no consistent multivariate analysis variables among the series to predict for an increase in Gleason score.ConclusionMore than one third of the patients were found to have been undergraded based on their initial prostate biopsy. Therefore, 1 biopsy alone may not be sufficient to offer active surveillance as an option. Further exploration is necessary to better ensure low-risk disease before active surveillance.