Population-based randomized trial of results after four years of screening for prostate cancer with PSA and MRI

The GÖTEBORG-2 ISRCTN study in Sweden invited men aged 50 to 60 years to undergo PSA-screening; men with a PSA level of 3 ng per ml or higher were randomized to a systematic biopsy group, in which they underwent systematic biopsy and, if suspicious lesions were found on MRI, targeted biopsy (n=6578), or to a MRI-targeted biopsy group, in which they underwent MRI-targeted biopsy only (n=6575). Men were invited for repeat screening 2, 4 or 8 years later, depending on the PSA level. After a median follow-up of 3.9 years, prostate cancer had been detected in 2.8% of men in the MRI-targeted biopsy group and 4.5% of men in the systematic biopsy group. The relative risk of detecting clinically insignificant cancer (ISUP grade 1) in the MRI-targeted biopsy group as compared with the systematic biopsy group was 0.43 (95% CI 0.32-0.57); whereas the relative risk of detecting clinically significant cancer IUSP grade ≥2) was 0.84 (0.66-1.07). The number of advanced or high-risk cancers detected (by screening or as interval cancer) was 15 in the MRI-targeted biopsy group and 23 in the systematic biopsy group (RR 0.65; 95% CI 0.34-1.24). Five severe adverse events occurred (three in the systematic biopsy group and two in the MRI-targeted biopsy group). The authors conclude that omitting systematic biopsy in patients with negative MRI results eliminated more than half of diagnoses of clinically insignificant prostate cancer, and the associated risk of having incurable cancer diagnosed at screening or as interval cancer was very low.