Active surveillance in favorable intermediate risk prostate cancer: outstanding questions and controversies.

Abstract

Active surveillance has become the preferred management strategy for patients with low risk prostate cancer, but it is unclear if active surveillance can be safely extended to favorable intermediate risk (FIR) prostate cancer patients. Furthermore, defining a favorable intermediate risk prostate cancer population safe for active surveillance remains elusive due to paucity of high-level data in this population. This article serves to review relevant data, particularly the safety of active surveillance in grade group 2 patients, and what tools are available to aid in selecting a favorable subset of intermediate risk patients. Active surveillance studies with long-term data appear to report worsened survival outcomes in intermediate risk patients when compared to those undergoing definitive treatment, but there exists a subset of intermediate risk patients with nearly equivalent outcomes to low risk patients on active surveillance. Tools such as percentage and total length of Gleason pattern 4, tumor volume, prostate specific antigen density, magnetic resonance imaging, and genomic modifiers may help to select a favorable subset of intermediate risk prostate cancer appropriate for active surveillance. Active surveillance is a viable strategy in select patients with low volume group grade 2 (GG2) prostate cancer. Prospective and retrospective data in the FIR population appear to be mostly favorable in regards to survival outcomes, but there exists some heterogeneity with respect to long-term outcomes in this patient population.