New Method Improves the Accuracy of Prostate Cancer Biopsies

Researchers have found that combining MRI-targeted biopsy and 12 core systematic biopsy for men with MRI-visible prostate lesions could help prevent misclassifications of prostate cancer. The study was published on March 5, 2020 in the New England Journal of Medicine.

The standard biopsy method for prostate cancer, which involves taking 12 core samples from different parts of the prostate, is associated with diagnostic inaccuracy that contributes to both under- and overdiagnosis of prostate cancer. Researchers investigated whether adding MRI-targeted biopsy to 12 core systematic biopsy would improve the accuracy of the biopsy results.

Doctors performed both 12 core systematic biopsy and MRI-targeted biopsy on 2103 men with MRI-visible prostate lesions and classified them into one of three grade groups based on the presence of clinically insignificant disease, the presence of cancer with favorable intermediate risk or worse, or the presence of cancer with unfavorable intermediate risk or worse. Of the men who underwent biopsy, 19.2 percent needed a radical prostatectomy.

After radical prostatectomy, researchers performed histopathological analysis on the surgical specimens and classified each into one of the three grade groups. They then compared the grade group determined by each biopsy method and with the methods combined to the grade group determined using histopathological analysis. Combining both biopsy methods led to the lowest rate of reclassification with only 3.5 percent of cases being reclassified—far better than the 8.7 percent and 16.8 percent of cases that had to be reclassified when using MRI-targeted biopsy and systematic biopsy respectively.

The results suggest that combining these two biopsy methods could help improve detection of prostate cancer and prevent misclassification of cancer severity.