A 4Kscore cut-off of 7.5% for prostate biopsy decisions provides high sensitivity and negative predictive value for significant prostate cancer.

To evaluate the 4Kscore test's low risk cut off of 7.5% as the indication to proceed with a prostate biopsy by combining data from two independent prospective multicentre trials in the United States which have validated the 4Kscore test as a continuous score to predict clinically significant prostate cancer.

We analyzed the data from 2 prospective multicenter trials in the United states to determine the number of men who could safely avoid a prostate biopsy and the presence of clinically significant cancers detected, at a 4Kscore cut off of 7.5%. We evaluated this in the entire cohort, and three subgroups of men aged 45-75 years with a total PSA between 3.0 - 10.0 ng/ml, African American, and non-African American men.

The analysis included 1378 patients. The combination analysis at a 7.5% threshold to decide upon a prostate biopsy, was associated with a 32% biopsy reduction. A total of 21 men (4.8%) with a low risk 4Kscore had International society of Urological Pathology, prostate cancer Grade group (GG) 2 or 3 cancer, leading to a sensitivity of 94% for detecting GG ≥ 2 cancer, and a negative predictive value (NPV) of 95%. There were no GG ≥ 4 cancers with a low risk 4Kscore. Analyses in various subgroups afforded similar results.

A 4Kscore test cut-off of 7.5% allowed a significant biopsy reduction, while maintaining high sensitivity and NPV for detecting and ruling out aggressive prostate cancer.

Urology. 2020 Nov 17 [Epub ahead of print]

Amit S Bhattu, Stephen M Zappala, Dipen J Parekh, Sanoj Punnen

Department of Urology, University of Miami Miller School of Medicine, Miami, Florida. Electronic address: ., Andover Urology, Andover, MA., Department of Urology, University of Miami Miller School of Medicine, Miami, Florida; Sylvester comprehensive cancer centre, Miami, Florida.