Genitourinary Pathology Society and International Society of Urological Pathology White Paper on Defining Indolent Prostate Cancer: Call for a Multidisciplinary Approach

The goal of this white paper is to help in identifying a path towards a meaningful multidisciplinary solution to the pervasive problem of overdiagnosis of indolent prostate cancer (PC) and its downstream negative effects. Our emphasis is not on the renaming debate for grade group (GG) 1 PC, but on reviewing the evidence base regarding the current state, limitations, gaps, and future directions for detection of indolent PC. We explain why the optimal diagnosis of indolent PC—defined as a low-volume, well-differentiated acinar neoplasm with invasive histologic features that do not spread outside the prostate, become symptomatic, or shorten a patient’s life if left untreated—requires coordination among clinicians, radiologists, and pathologists rather than relying on pathologists alone. We also show why clinically insignificant PC and indolent PC, despite considerable overlap, do not necessarily mean the same entity.