Prostate cancer screening: Decision-making when MRI results are inconclusive for cancer (PI-RADS 3)

Many patients who receive prostate magnetic resonance imaging are classified as Patient Imaging Reporting and Data Systems level 3 (PI-RADS 3), which is inconclusive for cancer. An important question is whether PI-RADS 3 patents should receive a biopsy. Prostate biopsy has a 4.6% chance of complications including a 1.3% chance of a hospital or emergency room visit. I critically examine the literature on the standard endpoint for PI-RADS 3 decision-making, namely clinically significant prostate cancer (csPCa) determined on biopsy. Some methods for estimating the probability of csPCa are statistically flawed. Importantly, even if there were no methodological flaws, these estimates have limited information for decision-making because the benefit of detecting csPCa on biopsy is not well established. Therefore, PI-RADS 3 patients should consider events after biopsy. The prostate testing for cancer and treatment trial of patients with localized prostate cancer found similar probabilities of prostate cancer death among patients randomized to active monitoring, prostatectomy, and radiotherapy. Adding perspective, based on calculations from the results of this trial, the probability of prostate cancer death is much smaller than the probability of death from other causes, particularly in older patients. Therefore, for PI-RADS 3 patients who would choose active monitoring if diagnosed with csPCa on biopsy, a reasonable decision is no biopsy with active monitoring.