Combined Biopsy Approach to Prostate Cancer Detection
Posted: Monday, March 16, 2020
Although the use of the standard 12-core systematic prostate biopsy has led to over- and underdiagnosis of prostate cancer, a recent study found that combining systematic biopsies with MRI-targeted biopsies seemed to significantly improve cancer detection. However, the report, published in The New England Journal of Medicine, indicated that MRI-targeted biopsies alone tended to underestimate tumor histologic grade.
“With the addition of MRI-targeted biopsy to systematic biopsy, we can now identify the most lethal cancers within the prostate earlier, providing patients the potential for better treatment before the cancers spread,” Peter A. Pinto, MD, of the National Cancer Institute, Bethesda, Maryland, stated in a National Cancer Institute press release.
Overall, 2,103 men with MRI-visible lesions underwent MRI-targeted and systematic prostate biopsies. The combined methods were used to classify the disease according to grade. Grade group 1 referred to clinically insignificant disease, whereas grade group 3 or higher referred to clinically significant disease with unfavorable risk or worse.
Via the combined methods, 1,312 patients (62.4%) were diagnosed with prostate cancer. Of them, 404 patients (19.2%) underwent radical prostatectomy. The MRI-targeted method detected significantly lower rates of cancer than the systematic biopsy method for grade 1 cancers (P < .01). However, for clinically significant disease, MRI-targeted biopsies detected significantly higher rates of cancer (P < .01). Prostate cancer was diagnosed in 208 more men (9.9%) when the combined approach was used than with either method alone. Additionally, 458 men (21.8%) were upgraded to a higher grade level with the combined approach. Had the men undergone MRI-targeted biopsies alone, 8.8% of patients with at least grade 3 disease would have been misclassified. Of those patients who had radical prostatectomy, histologic upgrades to grade 3 or higher were substantially lower with combined biopsy (3.5%) than with MRI-targeted (8.7%) or systematic biopsy (16.8%).
Disclosure: For full disclosures of the study authors, visit nejm.org.