Negative transrectal ultrasound biopsy tied to low prostate cancer death

Prostate cancer-specific mortality is very low among men with negative transrectal ultrasound (TRUS) biopsies, particularly those with prostate-specific antigen (PSA) <10 ng/ml, reports a study.

“This raises serious questions about the routine use of magnetic resonance imaging (MRI) targeting for initial prostate biopsy and suggests that MRI targeting should only be recommended for men with PSA >10 ng/ml after negative biopsy,” the authors said.

This study included men who underwent initial TRUS biopsies between 1 January 1995 and 31 December 2016 in Denmark. Of these, 37,214 had a negative initial TRUS biopsy and 6,389 underwent a rebiopsy.

The authors analysed the cause-specific mortality risk with competing risks. They also examined the diagnosis of Gleason score ≥7 prostate cancer following negative biopsies with multivariable logistic regression, including time to rebiopsy, PSA, age, and digital rectal examination.

At 15 years, the prostate cancer-specific mortality was 1.9 percent (95 percent confidence interval [CI], 1.7‒2.1). For men with PSA <10 and >20 ng/ml, mortality due to prostate cancer was 1.3 percent (95 percent CI, 0.9‒1.6) and 4.6 percent (95 percent CI, 3.4‒5.8), respectively.

Twelve percent of the TRUS rebiopsies were Gleason score ≥7, and the longer the time to rebiopsy, the higher the risk of having a Gleason score ≥7 (p<0.001). Of note, deaths following rebiopsy were comparable to that after initial biopsy.

“MRI-targeted prostate biopsy has been shown to find many high-grade prostate cancers in men with concurrent negative TRUS systematic biopsy,” the authors said. “The oncologic risk of such tumours can be explored by looking at long-term outcomes of men with negative TRUS biopsy followed without MRI.”