BETHESDA, MD USA (UroToday.com) - Dr. Simpa Salami presented a study which compared detection rates of clinically significant prostate cancer between a standard 12-core prostate biopsy and biopsies performed using an MRI/TRUS fusion platform targeting suspicious lesions seen on MRI. This study looked at a subset of patients with at least one prior negative biopsy who were enrolled prospectively in an MRI/TRUS fusion biopsy trial. All patients underwent a 3T multiparametric MRI with an endorectal coil, and suspicious lesions seen on MRI were graded by 3 radiologists on a 5-point Likert scale.
In total, 140 men were included in the study, and the cancer detection rate in this group with at least one prior negative biopsy was 65%. Patients in whom clinically significant prostate cancer was detected had a higher PSA (10.7 vs 8.0, p=0.005), higher PSAD (0.25 vs 0.14, p < 0.001), smaller prostate volume on MRI (47cc vs 56cc, p=0.04), and larger MRI target lesion volume (0.49cc vs 0.25cc, p=0.002) compared to those in whom no cancer was detected, or only indolent cancer was detected. The cancer detection rate of the standard biopsy and fusion biopsy were similar at 49% and 52%, respectively. The authors found, however, that the fusion biopsy was more likely to detect clinically significant cancers (48% vs 31%, p < 0.001). As compared to the fusion biopsy, the standard biopsy missed 19 of 72 (26%) clinically significant cancers -- most of which were in the anterior and central portions of the gland on MRI. In contrast, in patients with lesions highly suspicious for malignancy (i.e., Likert score ≥ 4) the fusion biopsy missed only 3.5% of clinically significant cancers. The AUC of the multiparametric MRI in predicting clinically significant cancer in this study was 0.82, significantly higher than either PSA (AUC 0.64) or PSAD (AUC 0.69) (p < 0.001).
The authors concluded that the use of a fusion biopsy could improve detection of clinically significant cancers in patients with previous negative biopsies. One limitation that should be noted, however, is that the true ability of the fusion biopsy to detect clinically significant cancers is not fully assessed in this study given only biopsy-identified cancers were included. Due to the study design, it does not capture clinically significant cancers that were missed by both the fusion biopsy as well as the standard biopsy. A comparison of targeted fusion biopsy outcomes to radical prostatectomy specimens would allow for a more accurate assessment of the ability of the fusion biopsy to detect any clinically significant cancers present. The authors note that the standard biopsy added very little clinical value to the targeted fusion biopsy, calling into question the necessity of random sampling of the prostate in patients with high suspicion lesions on MRI. Further research will be necessary to confirm this conclusion before the standard 12-core biopsy can be deemed obsolete.
Simpa Salami, MD, MPH,1 Eran Ben-Levi, MD,1 Oksana Yaskiv, MD,1 Laura Ryniker, MD,1 Baris Turkbey, MD,2 Louis Kavoussi, MD, MBA,1 Robert Villani, MD,1 and Ardeshir Rastinehad, DO1
1The Smith Institute for Urology, Hofstra North Shore – LIJ School of Medicine, New Hyde Park, NY; 2enter for Interventional Oncology, Urologic Oncology Branch, National Cancer Institute, Bethesda, MD
Timothy Ito, MD* from the 2014 Winter Meeting of the Society of Urologic Oncology (SUO) "Defining Excellence in Urologic Oncology" - December 3 - 5, 2014 - Bethesda, MD USA
*Fox Chase Cancer Center, Philadelphia, PA USA