Active surveillance eligibility of MRI-positive patients with grade group 2 prostate cancer: a pathological study

Abstract

Purpose: To assess the final pathology risk in MRI-positive grade group (GG) 2 prostate cancer (PCa) patients undergoing targeted (TB) and systematic (SB) biopsies, and thereby, the possibility of active surveillance (AS) in this population.

Patients and methods: We included 242 consecutive men diagnosed with GG2 PCa by a combination of SB and software-based fusion TB undergoing a radical prostatectomy (RP). The primary endpoints were the pathological findings in RP specimens, including favourable disease which was defined by a pT2 and GG1-2 disease.

Results: The rate of upgrading was 33% including 3% of GG 4-5 disease. MRI lesion size (p = 0.038) and tumor length per core (p < 0.001) were significantly lower in case of favourable pathology. Only 34.2% of not organ-confined disease was reported when only SB were positive, compared with 45.7% and 57.1% when GG2 was detected on TB only and on TB plus SB, respectively (p = 0.035). The number of positive cores on SB was significantly higher in not organ-confined disease (4.3 versus 2.9; p = 0.005). The risk of not organ-confined disease was only 20.8% in men who had a PSAD ≤ 0.20 ng/ml/gr, 1-2 positive biopsies and a maximal tumor length ≤ 6 mm per core, compared with 52.3% in men who did not fulfil all these criteria (p = 0.003).

Conclusions: This study identified clinical, imaging, and pathological factors that were significantly associated with the final pathology risk. In case of positive MRI followed by TB showing GG2, AS could be offered in patients having a PSAD ≤ 0.20, a tumor length ≤ 6 mm and 1-2 positive cores.

Keywords: Active surveillance; Biopsy; Fusion biopsies; Intermediate risk; Prostate cancer; Radical prostatectomy; Targeted biopsies, MRI.