Use of MRI led to fewer biopsies and fewer diagnoses of clinically insignificant cancer.

Increasingly, magnetic resonance imaging (MRI) is being incorporated into prostate cancer screening; the ultimate goal is fewer biopsies and less overdiagnosis. In this Swedish trial, 13,000 middle-aged men (age range,
50 to 60 years) who had prostate-specific antigen (PSA) screening tests were randomised into two groups, as follows:  

• in the ‘MRI-targeted biopsy’ group, patients with elevated PSA levels (3 to 10 mcg/L) underwent MRI, and suspicious lesions were biopsied; no biopsies were done if MRI showed no lesions 
• in the ‘systematic biopsy’ group, patients with elevated PSA also underwent MRI, but these patients had standard systematic biopsies (10 to 12 cores) plus biopsies of suspicious lesions identified on MRI.

Patients who had no biopsies or negative biopsies returned at specified intervals for additional rounds of screening, with further evaluation according to their randomised protocols.

During median participation of four years, patients in the MRI-targeted group were significantly less likely than those in the systematic group to have undergone at least one biopsy (4% vs 9%). Prostate cancer was diagnosed less frequently in the MRI-targeted group than in the systematic group (2.8% vs 4.5%) – a difference mainly attributable to fewer clinically insignificant cancers (1.0% vs 2.4%). Cancers that were likely to be incurable were diagnosed in only 23 and 15 patients in the MRI-targeted and systematic-biopsy groups, respectively. 

Comment: Use of MRI as described here led to fewer biopsies and fewer diagnoses of clinically insignificant cancers – with no obvious clinical downside – during follow up averaging about four years. Information on important longer-term outcomes (metastatic disease and death) will not be available for at least several more years, but this study likely will influence practice in the meantime.

Allan S. Brett, MD, Clinical Professor of Medicine, University of Colorado School of Medicine, Aurora, USA.

Hugosson J, et al. Results after four years of screening for prostate cancer with PSA and MRI. N Engl J Med 2024; 391: 1083-1095.

The summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine, Oncology and Hematology