In men undergoing a first prostate biopsy, the optimal method for detecting clinically significant cancer (grade group 2 or higher) is the combination of systematic biopsy and targeted biopsy of lesions visible on magnetic resonance imaging (MRI), according to investigators.
Leonard S. Marks, MD, of the University of California, Los Angeles, and colleagues designed the PAIREDCAP (Prospective Assessment of Image Registration for Diagnosis of Prostate Cancer) trial to answer outstanding questions about the use of MRI-guided prostate biopsy. A total of 300 biopsy-naïve men (aged 45 to 80) with an elevated PSA level (less than 25 ng/mL) or an abnormal digital rectal examination had multiparametric MRI. Of these, 248 (mean age 65.5 years; 79.4% white) displayed suspicious lesions on MRI (i.e., a PI-RADS version 2 score of 3 or higher) and underwent 12-core transrectal ultrasound-guided systematic biopsy, followed by cognitive targeted biopsy (3 cores), and software-assisted fusion targeted biopsy (3 cores) at the same sitting. During cognitive biopsy, a radiologist viewing the MRI directed the clinician to aim at regions of interest. In software fusion biopsy, the MRI and ultrasound fusion device (Artemis) produced a 3D model of the prostate that included suspicious lesions to enable targeting. The remaining 52 men (mean age 63.6 years; 75% white) with no visible lesions on MRI (i.e., a PI-RADS version 2 score of less than 3) underwent systematic biopsy alone.
Overall, 70.2% of significant cancers were detected by combining systematic and targeted biopsy, according to results published online in JAMA Surgery. Cognitive targeted biopsy alone detected 46.8%, systematic sampling alone, 60.1%, and either cognitive or software fusion biopsy, 62.1%. The distribution of Gleason scores appeared similar among biopsy methods. As PI-RADS version 2 score or PSA density increased, so did the chances of significant cancer.
According to the investigators, 11.5% to 33.3% of clinically significant cancers would have been missed by using only a single biopsy method. In the subset of 52 men who underwent systematic biopsy alone, for example, 15% had clinically significant cancer missed by MRI.
“Our research suggests that the different biopsy methods identify different tumors,” Dr Marks stated in a university news release. “To maximize our ability to identify prostate cancer, we need to take advantage of all the information we can. Our cancer detection rate, while using different methods in tandem, surpasses that from using either method alone. In this case, one plus one equals three.”
When the MRI is negative for lesions, men at risk of prostate cancer (due to elevated PSA, a prostate nodule, or family history) should still receive systematic biopsy, he noted.
In an accompanying editorial, Ahmad Shabsigh, MD, and Cheryl T. Lee, MD, of Ohio State University Wexner Medical Center in Columbus, offered a slightly different perspective: “A few important lessons can be learned from this study: first, relying on targeted biopsy alone is suboptimal; second, if the urologist does not have a fusion machine, cognitive biopsy is still essential. The results reflect the reality that multiparametric MRI is better than what clinicians have had, but there is still a way to go.”
Elkhoury FF, Felker ER, Kwan L, et al. Comparison of targeted vs systematic prostate biopsy in men who are biopsy naïve: The Prospective Assessment of Image Registration in the Diagnosis of Prostate Cancer (PAIREDCAP) Study. JAMA Surg. (Published online June 12, 2019.) doi:10.1001/jamasurg.2019.1734
Study shows more effective method for detecting prostate cancer (news release). University of California, Los Angeles (UCLA), Health Sciences; June 11, 2019.
Shabsigh A and Lee CT. Closing the loop on the role of multiparametric magnetic resonance imaging–targeted prostate biopsy. JAMA Surg. (Published online June 12, 2019.) doi:10.1001/jamasurg.2019.1735