Study Says Targeted Biopsy with MRI Reduces Overdiagnosis of Prostate Cancer by Half

Is a systematic biopsy necessary for all men with elevated prostate-specific antigen (PSA) levels?

Emerging research findings from a study of 17,980 men who had prostate cancer screening showed the use of magnetic resonance imaging (MRI)-targeted biopsy reduced the risk of diagnosing Gleason 3+3 cancers in half in comparison to the use of systematic biopsy.

For the study, recently published in the New England Journal of Medicine, researchers compared the use of systematic biopsy and multiparametric MRI-targeted biopsy in a reference group of 5,994 participants to the use of MRI-targeted biopsy only in an experimental group of 11,986 participants. In the experimental group, the study authors reserved the use of MRI-targeted biopsy for men who had Prostate Imaging Reporting and Data System (PI-RADS) scores of 3 to 5.

Out of the 11,986 participants in the experimental group, 66 men (0.6 percent) were diagnosed with Gleason 3+3 scores (clinically insignificant cancer) whereas 72 men in the reference group of 5,994 participants (1.2 percent) had Gleason 3+3 scores, according to the study.

“Since the frequent detection of small Gleason 3+3 cancers after PSA screening is regarded as a major contributor to the high incidence of potentially harmful overdiagnosis of prostate cancer, this finding is of importance,” wrote lead study author Jonas Hugosson, M.D., Ph.D., who is affiliated with the Department of Urology at Sahlgrenska University Hospital in Gothenburg, Sweden, and colleagues. “This strategy also considerably reduced the percentage of biopsies in participants in the experimental group who had elevated PSA levels.”

(For related articles on prostate cancer imaging, visit https://www.diagnosticimaging.com/clinical/prostate-cancer .)

The study authors also noted tumor size differences between the clinically insignificant cancers diagnosed in the experimental and reference groups.

“Gleason 3+3 cancers that were detected in the experimental group were in general larger than those detected in the reference group and may potentially have had clinical importance, especially in this relatively young age group (median age of 56) in which grade progression might occur with increasing age,” said Hugosson and colleagues.

While acknowledging 19 percent fewer cases of clinically significant cancers diagnosed in the experimental group, the researchers said the cancers detected in 10 participants with systematic biopsy alone “were mostly small and all had a Gleason score of 3+4 with a small amount of Gleason pattern 4 detected.” Four of these patients had radical treatment and the remaining six patients had active surveillance, according to Hugosson and colleagues.

(For additional related articles, see “Can MRI-Based Prostate Cancer Screening be a Viable Alternative to PSA Testing?,” “Study Assesses PET Agent for Detecting Pelvic Lymph Node Metastases in Patients with Prostate Cancer?” and “Could an Emerging AI Platform Supplant Traditional MRI for Assessing Prostate Cancer?”)