ORLANDO, FL, USA (UroToday.com) - Given the conflicting data on of the effect of prostate cancer screening on the reduction in mortality, along with the known high numbers needed to screen and treat, a number of groups have focused their efforts on biomarkers that can provide improved risk stratification. Harms of prostate biopsy include increasing risk of infection, urinary complications, costs, and emotional stress. Thus, better markers that are focused on identification of aggressive cancers are needed so that biopsy can be foregone in a number of men who are not at risk of death from disease. Dr. Sanoj Punnen from the University of Miami presented his group’s data on a new test, the 4K Score.
The 4K Score is a blood test that combines four kallikrein assays with clinical information in an algorithm that reports the probability of high-grade prostate cancer on biopsy of the prostate. The seven elements of the 4K Score include total PSA, free PSA, intact PSA, and hK2, along with DRE, prior biopsy, and patient age. The test was used prospectively at 26 U.S. centers in 1 000 men scheduled for prostate biopsy regardless of PSA or clinical findings. The primary outcome assessed was finding of Gleason 3+4 (defined as high-risk) prostate cancer on TRUS biopsy.
The group found Gleason 3+4 in 10.7% of patients (23% of cancers), 4+3 in 5.8% of patients (12.6%), Gleason 8 in 3.5% of patients (7.4%), Gleason 9 in 2.6% of patients (5.5%) and Gleason 10 in 0.3% of patients (0.6%). Overall, 22.8% of patients had high-risk disease, while 77.2% had negative biopsies or Gleason 6 cancer. The 4K Score demonstrated near perfect calibration when comparing actual to predicted high risk cancer, and had a greater accuracy when comparing AUC (0.82) vs that of the PCPT 2.0 (0.74, p < 0.0001). If a 9% probability of high-grade cancer was used as a threshold for biopsy of the prostate, 434 (43%) unnecessary biopsies could have been avoided, while delaying diagnosis of only 24 (2.4%) high-grade cancers.
Dr. Punnen concluded that the 4K Score is accurate in the detection of high grade prostate cancer, can provide personalized risk prediction, and can lead to a significant reduction in unnecessary prostate biopsies.
Presented by Sanoj Punnen, MD at the 2015 Genitourinary Cancers Symposium - "Integrating Biology Into Patient-Centric Care" - February 26 - 28, 2015 - Rosen Shingle Creek - Orlando, Florida USA
University of Miami, Coral Gables, FL USA
Reported by Nikhil Waingankar, MD, medical writer for UroToday.com