A 4Kscore Cut-off of 7.5% for Prostate Biopsy Decisions Provides High Sensitivity and Negative Predictive Value for Significant Prostate Cancer

• Published in: Urology (Ridgewood, N.J.) Vol. 148; pp. 53 - 58
• Main Authors: Bhattu, Amit S., Zappala, Stephen M., Parekh, Dipen J., Punnen, Sanoj
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2021
• Subjects: Adult; African Americans; Age Factors; Aged; Biopsy - statistics & numerical data; Clinical Trials as Topic; Digital Rectal Examination; Early Detection of Cancer; Humans; Male; Middle Aged; Neoplasm Grading; Predictive Value of Tests; Prostate - pathology; Prostate-Specific Antigen - blood; Prostatic Neoplasms - blood; Prostatic Neoplasms - ethnology; Prostatic Neoplasms - pathology; Reference Values; Sensitivity and Specificity; Tissue Kallikreins - blood
• ISSN: 0090-4295; 1527-9995
• DOI: 10.1016/j.urology.2020.11.008

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 2 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 3 subgroups of men aged 45-75 years with a total prostate specific antigen between 3.0 and 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 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.