Investigators have found that combining a prostate magnetic resonance imaging (MRI) scan with a prostate-specific antigen (PSA) density test may help diagnose clinically significant prostate cancer and avoid unnecessary biopsies, according to a recent systematic review and meta-analysis published by Haj-Mirzaian et al in JAMA Network Open.
Background
Clinically significant prostate cancer, which has a high chance of being life-threatening, includes cancer cells that look more aggressive or are found outside the prostate gland. Older men often experience enlarged prostates or potential prostate cancer. Estimates suggest that in 2024, there will be approximately 300,000 new cases of prostate cancer in the United States.
“Prostate cancer is the second most common cancer in men worldwide, but we need to be able to identify patients who require prostate biopsy while avoiding unnecessary procedures and minimizing the risk of missing clinically significant prostate cancer,” said co–study author Adam Kibel, MD, Chair of the Department of Urology at Brigham and Women’s Hospital.
Prostate biopsies—which are traditionally needed to understand how aggressive the cancer cells are—can be uncomfortable, invasive, and expensive. Although previous research has demonstrated that not all prostate cancers require treatment or even biopsies, identifying these cases can be difficult.
"With this new analysis, we looked to see how MRI can help urologists decide which patients to biopsy and which patients may not need aggressive diagnosis and treatment,” explained senior study author Ramin Khorasani, MD, MPH, the Philip H. Cook Professor of Radiology at Harvard Medical School and Radiology Vice Chair for Quality and Safety at Brigham and Women’s Hospital.
Study Methods and Results
In the recent study, the investigators examined the efficacy of a novel approach combining MRI-based prostate imaging reporting and data system scores with PSA density tests—with the goal of determining which patients had clinically significant prostate cancer without including information from biopsies. They noted that MRI-based prostate imaging reporting and data system scores rank prostate lesions from 1 to 5, in which a score of 1 signifies that the cancer is highly unlikely to be clinically significant and 5 signifies that the cancer is highly likely to be clinically significant. PSA density is the PSA blood level divided by the prostate’s volume as determined by MRI.
The study built on prior research published by Naik et al in the Journal of the American College of Radiology in 2022, in which investigators found that using MRI-based prostate imaging reporting and data system scores and PSA density test cutoffs could pinpoint up to 50% of patients who didn’t require a biopsy.
In the recent study, the investigators used data from 72 previously published studies to evaluate the MRI-based prostate imaging reporting and data system scores, PSA density test results, and determination of clinical significance from biopsy of over 36,000 patients with prostate cancer. The investigators sought to determine whether their earlier findings were accurate in a more diverse sample set.
The investigators discovered that prostate biopsies may be unnecessary for patients with MRI-based prostate imaging reporting and data system scores under 4 and PSA density tests below 0.10 ng/mL2. Further, using specific MRI-based prostate imaging reporting and data system scores and PSA density test cutoffs, physicians could confidently skip 50% or 30% of biopsies while only missing a respective 5% or 3% of clinically significant cancers.
Conclusions
"In the workup of men suspected of having prostate cancer, prostate MRI findings combined with PSA density measurement can help [physicians] decide which patients to biopsy," emphasized Dr. Khorasani.
The investigators plan to use their recent analysis to develop a patient-level scoring system that urologists can use to evaluate their patient’s need for a prostate biopsy.
“[P]atient-tailored prostate biopsy decisions based on information from MRI and blood tests could prevent unnecessary procedures while maintaining high sensitivity,” underscored Dr. Kibel. "These data give us the confidence to say that in some cases, we can safely follow men with testing rather than aggressively pursue a biopsy in all cases. By making this information available to physicians and patients, we can help them make a more informed decision about undergoing a biopsy,” he concluded.
Disclosure: The research in this study was supported by the Center for Evidence-Based Imaging and in part by the Agency for Healthcare Research and Quality and Siemens Healthineers. For full disclosures of the study authors, visit jamanetwork.com.
