Histopathological characteristics of microfocal prostate cancer detected during systematic prostate biopsy.

Objective To evaluate the prevalence of adverse pathological features and the percentage of multifocal and/or bilateral disease in a series of patients who underwent radical prostatectomy (RP) for unique, microfocal prostate cancer (miPCa) detected on prostate biopsy in the pre-active surveillance (AS) era. Patients and Methods In this retrospective, multi-institutional study, we analysed the clinical records of 131 consecutive patients who underwent either retropubic or robot-assisted RP for miPCa at two referral centres from January 2000 to December 2011. miPCa was defined as a neoplastic lesion present in <= 10% of core with biopsy Gleason score not applicable or biopsy Gleason score 6. Results There were 17 (13%) pT3-4 prostate cancers and a single case (0.8%) of pN+ tumour. Moreover, 31 (24.1%) patients had a Gleason score of >6 in the RP specimen. Therefore, unfavourable pathological features (pT3-4/N+ and/or Gleason score >6) were present in 40 (30.5%) patients. The median interquartile range) prostate-specific antigen (PSA) density was 0.11 (0.09-0.17) and 0.16 (0.11-0.24) ng/mL/mL in patients with favourable and unfavourable pathological characteristics, respectively (P = 0.003). The receiver operating characteristic curve had an area under the curve value of 0.67 (95% confidence interval 0.56-0.77) for PSA density to predict the risk of unfavourable pathological features. Conclusion Patients with miPCa who are candidates for an AS protocol should be adequately informed that in approximate to 30% of cases the cancer might be locally advanced and/or with a Gleason score of >6. Those unfavourable pathological characteristics could be predicted by the PSA density value. Further studies should investigate the role of a more extensive biopsy sampling to reduce the risk of under-staging and/or under-grading in patients with an initial diagnosis of miPCa.