A high 4Kscore predicts a greater likelihood of prostate cancer progression on active surveillance independent of National Comprehensive Cancer Network (NCCN) risk category and MRI findings, investigators reported at the Society of Urologic Oncology’s 23rd annual meeting in San Diego, California.
The 4Kscore identifies men with grade group 2 or higher disease in men with clinical suspicion of prostate cancer, Helen Y. Hougen, MD, of the Miller School of Medicine at the University of Miami in Florida, and colleagues explained. Little is known about the utility of the 4Kscore in men undergoing active surveillance for prostate cancer, however, particularly when incorporating MRI findings, they pointed out.
Dr Hougen’s team collected prostate MRI findings, 4Kscore, and biopsy information from 166 men enrolled in the MAST (MRI-Guided Active Selection for Treatment of Prostate Cancer) study within 1 year of diagnosis and again at 12, 24, and 36 months. MAST is a single-center, single-arm prospective study of men undergoing active surveillance for low- to intermediate-risk prostate cancer.
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Dr Hougen’s team categorized 4Kscore as low (7% or less), intermediate (7%-19%), and high (20% or greater). The primary outcome was disease progression, defined as more than 4 cores with any grade cancer, more than 2 cores with grade group 3+4 cancer, any single core with grade group 4+3 cancer, a grade group 3+3 at diagnosis that was upgraded to grade group 3+4, or any treatment regardless of histologic progression, they explained.
In all, 79 patients (47.6%) progressed during the study period. Men who progressed had a significantly higher median baseline 4Kscore than those who did not (31% vs 14%), Dr Hougen and colleagues reported. Patients with a 4Kscore of 20% or higher had a significantly higher cumulative incidence of progression by 36 months compared with patients who had a lower 4K score (72.5% vs 41.0%).
On multivariable analysis, a 4Kscore of 20% or higher independently predicted a 1.7-fold increased risk for progression after adjusting for NCCN risk, age, and PIRADS score, according to the investigators.
The investigators noted that, as far as they are aware, their study is the first to prospectively evaluate the role of 4Kscore within an MRI-based protocol. Although further validation is needed, they stated that their results are promising and suggest that the 4Kscore may be a useful tool for clinical decision making in active surveillance.
The 4Kscore test evaluates 4 proteins in blood — total PSA, free PSA, intact PSA, and kallikrein 2 — in combination with patient age and previous biopsy and digital rectal examination findings.
Reference
Hougen HY, Reis IM, Prakash NS, et al. Baseline 4K score predicts progression on active surveillance in prostate cancer independently of clinical information and PIRADS score. Presented at: SUO 2022, November 30 to December 2, San Diego, California. Poster 79.
