Data published from a multicenter clinical trial that included Keck Medicine of USC suggests that magnetic resonance imaging (MRI) prior to a prostate biopsy could eliminate unnecessary cancer tests and optimize accuracy of any necessary testing.

The PRECISION trial examines the use of magnetic resonance imaging (MRI) prior to a prostate cancer biopsy to find potential targets, if any. Typically, when a patient has a clinical suspicion of prostate cancer due to elevated prostate specific antigen levels or an abnormal digital rectal exam, a biopsy can confirm the presence of prostate cancer. The biopsy consists of 10-12 needle core pricks into the prostate, which may damage nerves and cause side effects like erectile dysfunction, pain and bleeding. It is also possible for the biopsy to miss the tumor entirely and present a false negative, as cancer does not grow uniformly throughout the prostate.

The study, published in the New England Journal of Medicine, followed 500 men with clinical suspicion of prostate cancer. Roughly half were chosen for MRI-targeted biopsy, while the other half received a standard biopsy. For 28 percent of the men in the MRI-targeted biopsy group, imaging results did not suggest prostate cancer and they did not receive a biopsy. Imaging also successfully aided doctors in identifying biopsy targets — clinically significant cancer was detected in 38 percent of men in the MRI-targeted biopsy group versus 26 percent in the standard biopsy group, despite taking fewer needle cores from the targeted biopsies. Moreover, patients in the MRI-targeted group experienced fewer side effect following the biopsies.

“Given the many advancements in prostate cancer treatment, it is surprising that a fair amount of diagnostics is left to chance,” said Inderbir Gill, MD, chair and Distinguished Professor of Urology and Shirley and Donald Skinner Chair in Urologic Cancer. Gill is the principal investigator of the PRECISION trial at Keck Medicine and a co-author of the New England Journal of Medicine study. “We need a more strategic method that minimizes unnecessary biopsies without sacrificing vigilance, and the PRECISION trial has produced encouraging results thus far.”

One limitation of the study is the chance that men who did not receive a targeted biopsy based on their MRI could still have clinically significant cancer that would have been detected on a standard biopsy. While previous research in this space indicates that risk is low, Gill is leading a multicenter clinical trial alongside Mariana Stern, TITLE, that is testing the potential benefits of using a combination of MRI and ultrasound technology to diagnose prostate cancer.

— Mary Dacuma