How much does Gleason grade of follow‐up biopsy differ from that of initial biopsy in untreated, Gleason score 4–7, clinically localized prostate cancer?

Abstract

OBJECTIVE To compare histologic grades between an initial biopsy and a follow‐up biopsy in untreated, Gleason score (GS) 4–7, clinically localized prostate cancer. METHODS AND MATERIALS In a prospective single‐arm cohort study, clinically localized, GS 4–7, prostate cancer was managed with active surveillance alone, provided that a pre‐defined definition of disease progression was not met. One hundred five (63%) of a total of 168 eligible patients underwent a follow‐up prostate biopsy during surveillance. Median time to a follow‐up biopsy was 22 months (range: 7–81). Histologic grades between these two biopsies were compared to evaluate the extent of histologic grade change. RESULTS On the follow‐up biopsy, GS was unchanged in 33 patients (31%), upgraded in 37 (35%), and downgraded in 34 (32%). Eleven (10%) had upgrading by 2 Gleason points or more. Eight (8%) had upgrading to GS 8 (none to GS 9 or 10); of these, six were among those with upgrading by 2 Gleason points or more. Twenty‐seven (26%) had no malignancy on the follow‐up biopsy. Negative follow‐up biopsy was more prevalent in patients with a small volume of malignancy in the initial biopsy and a low baseline PSA. CONCLUSIONS No consistent change in histologic grade was observed on the follow‐up biopsy at a median of 22 months in untreated, GS 4–7, clinically localized prostate cancer. Upgrading to GS ≥8 or by 2 Gleason points or more was relatively uncommon. Prostate 67: 1614–1620, 2007.