Role of immediate confirmatory prostate biopsy to ensure accurate eligibility for active surveillance

Abstract

Objective: To assess the role of confirmatory prostate biopsy in the accurate risk assessment of patients with low risk prostate cancer eligible for active surveillance.

Methods: Patients electing active surveillance of their low grade, low volume prostate cancer with prostate-specific antigen <20 ng/mL, <cT2 disease who underwent confirmatory rebiopsy were included. Biopsy progression was defined as >2 core involvement or Gleason 7 disease on subsequent biopsies. Prostate-specific antigen, total number of cores on initial and rebiopsy, the presence of high-grade prostatic intraepithelial neoplasia, and prostate-specific antigen density, when available, were assessed as predictors of biopsy progression.

Results: Sixty patients were included. Median time to rebiopsy was 2 months. Nineteen patients (31.7%) had findings that excluded them from active surveillance. Despite rebiopsy findings, 7 patients elected for active surveillance, all of which eventually underwent treatment for continued biopsy progression. Of the 41 patients eligible for active surveillance after rebiopsy, 8% elected treatment, 74% remained on active surveillance, and 13% experienced biopsy progression. No cancer on rebiopsy was associated with a reduced risk of progression to treatment on active surveillance (odds ratio 0.14, P = .011). A microfocus of Gleason 4 pattern (odds ratio 16.0, P = .04) and high-grade prostatic intraepithelial neoplasia (odds ratio 7.29, P = .03) on initial biopsy were independent predictors of immediate rebiopsy progression. Prostate-specific antigen, prostate-specific antigen density, and the total number of cores were not significant.

Conclusion: Confirmatory rebiopsy aids in the accurate identification of low-risk patients for active surveillance as one-third are initially undergraded. Patients with high-grade prostatic intraepithelial neoplasia and any Gleason pattern 4 on initial biopsy are at highest risk and should be counseled regarding the risks of progression on active surveillance accordingly.