BERKELEY, CA (UroToday Inc.) - When patients show continued elevated PSA in the range of 5-15 ng/ml after two prior negative prostate biopsies, negative findings on endorectal MRI (EMRI) predicts a low likelihood of finding prostate cancer on subsequent biopsies.

J. Comet-Batlle and colleagues of Girona, Catalonia, Spain studied 92 patients with elevated PSA (>4 ng/ml) and/or abnormal digital rectal examination. They reported their results in European Urology. Each patient underwent EMRI before one or more episodes of sextant prostate biopsies. 61 patients then had 2, 27 had 3, 3 had 4 and 1 had 5 biopsies. Overall, 25 (27%) patients received the diagnosis of prostate cancer.

They performed stepwise analysis of predictive factors for positive biopsies by analyzing positive DRE, elevated PSA, free PSA/total PSA ratio, or EMRI. They observed that test accuracy for DRE was 69.5%, EMRI 55.6%, PSA 62%, and for PSA ratio 57.2%.

Accuracy achieved by combining PSA and EMRI results was 80%, and after combining DRE, PSA and EMRI reached 83%. However, when PSA value, negative prior biopsies and negative EMRI were combined, risk of a positive prostate biopsy became 8% after 2 biopsies, 5% after 3 biopsies and <3% after 4 biopsies.

They propose that in the presence of mildly elevated PSA and after two prior negative biopsies, negative EMRI predicts low risk of positive prostate biopsies and may allow more conservative observation and avoid repeat biopsy.

In an editorial comment, J.A. Spencer expresses some doubts regarding the limited number of patients in this study, and he questions its use in view of limited access to MRI in some areas. He suggests the need for a larger prospective study to test the present authors' hypothesis.

European Urology 2003;44:201-208

read other UroToday.com Editors Picks

Prostate Cancer Section