4Kscore® Test Accurately Predicts Aggressive Prostate Cancer in Second U.S. Prospective Study

Results Indicate Effectiveness of 4Kscore Test for All Men, Including African American Men

A prospective study conducted at various institutions within the U.S. Veteran’s Affairs (VA) Health System has found the 4Kscore Test accurately predicted the risk for aggressive prostate cancer in men prior to biopsy. The results of this study confirm the findings of an earlier, more extensive trial, which found that the 4Kscore Test more accurately discriminated between high-grade (aggressive) and low-grade (indolent) prostate cancer when compared with the Prostate Cancer Prevention Trial Risk Calculator (PCPTRC). [1] The new VA study also included a sample of African American participants statistically large enough to validate the results for both African American men and non-African American men.

Higher Rates for Aggressive Prostate Cancer & Prostate Cancer Death Among African Americans

Cancer researchers have long recognized that African American men are at a higher risk of prostate cancer and death from the disease than the general U.S. male population. Compared to non-Hispanic whites, African Americans are 1.6 times more likely to develop prostate cancer and two times as likely to die from the disease. Researchers who have explored the influence of environmental, socio-economic and metabolic factors have been unable to pinpoint the exact reasons for these disparities.[2]

African Americans also exhibit disease onset at an earlier age, present with more advanced-stage cancer at the time of diagnosis and have a higher incidence of aggressive prostate cancer. [3] An effective method for early cancer detection and identification of aggressive cancer holds the potential for lowering African American prostate cancer mortality and greatly benefiting these patients. Results of this new VA prospective study show that 4Kscore testing accurately predicts aggressive prostate cancer before biopsy, offering an effective method for early risk detection to narrow the gap for prostate cancer deaths between African Americans and the general population.

USPSTF Calls for More Research on Prostate Cancer Diagnosis in African American Men

When the U.S. Preventative Study Task Force (USPSTF) released a draft recommendation on the standard model of PSA-based screening for prostate cancer in 2017, the draft document did not include a separate recommendation specific to African American men—although the USPSTF recognized the higher incidence of prostate cancer in this group. Citing insufficient data for concluding that PSA-based screening might provide greater benefits for African American men compared with the general population, the task force instead suggested that clinicians “inform African American men about their increased risk of developing and dying of prostate cancer as well as the potential benefits and harms of screening so they can make an informed, personal decision about whether to be screened.”[4]

Since the USPSTF recommendations only concerned PSA-based screening, the 4Kscore Test was not mentioned as a screening alternative that physicians should offer to African American men. The USPSTF did highlight the need for additional research to study and develop new methods for prostate cancer detection and treatment for these men.

VA Study Validates Usefulness of 4Kscore Test as an Alternative for African American Men

The VA prospective study on 4Kscore testing included a significant percentage of African American participants, adding valuable research and clinical guidance for this population group. The independent study enrolled a total of 366 men at eight Veteran’s Affairs facilities across the
U. S. All of the men had been referred for prostate biopsy. Of these study participants, 208 men or 56% were African American. In addition, 134 men or 36% of participants presented with G7+ aggressive prostate cancer.

Before biopsies were performed, the study enrollees gave blood samples, which were tested for 4Kscore ascertainment. The results were then compared with a base model that included age, digital rectal examination (DRE) and PSA readings. Analysis showed that 4Kscore results accurately predicted a likelihood of aggressive prostate cancer and provided better clinical information than the base model for deciding whether to proceed with biopsy. The 4Kscore Test yielded results superior to the base model for both African American and non-African American participants. [5]

A Bridge Between Initial High PSA Readings & Biopsy

OPKO Health, the provider of the 4Kscore Test, urges clinicians to consider this more advanced test as a diagnostic test for all men, especially African American men and men with a family history of prostate cancer if they show clinical signs of prostate cancer. Providing information about 4Kscore testing allows practitioners to give patients advance testing when a patient’s PSA is abnormal during initial screening which may eliminate many of the concerns covered in the USPSTF draft recommendation, which noted the risks involved with overdiagnosis and treatment of low-risk cancers.

Patients in high-risk groups and their physicians are encouraged to follow an abnormal PSA reading with the 4Kscore Test to identify false positive results and avoid unnecessary biopsies. As confirmed by two U.S. prospective studies, the 4Kscore Test is highly accurate for distinguishing between high-grade (aggressive) and low-grade (indolent) prostate cancer and for providing better clinical information for treatment decision-making than the widely used PSA-based model alone.

Screening Accuracy Increases With 4Kscore Testing

A more comprehensive blood test than PSA-based screening, the 4Kscore Test measures the levels of four prostate biomarkers found in blood plasma: Free PSA, Total PSA, Intact PSA and Human Kallikrein 2 (hK2). This panel of four biomarkers was identified in over a decade of research by scientists at Memorial Sloan-Kettering Cancer Center and leading European institutions. The biomarker readings are analyzed using patient-specific information like age, DRE findings, and prior negative biopsy. Then, using a proprietary algorithm, the risk of aggressive prostate cancer (G7+) is calculated.

As confirmed by the VA prospective study and the previous validation study, the 4Kscore Test provides an accurate method for detecting the risk of aggressive prostate cancer and a useful diagnostic tool for reducing unnecessary biopsies that might leave a patient with harmful side effects and complications. Study results show that the 4Kscore Test provided more accurate decision-making data for high-risk African Americans, as well as the general population. In recognition of its value in identifying risk for aggressive prostate cancer, the 4Kscore Test has been included in the 2016 National Comprehensive Cancer Network and 2016 European Association of Urology Prostate Cancer Guidelines.



1. 4Kscore Blog Post. Study Confirms 4Kscore Accurately Predicts High-Grade Prostate Cancer (Access November 9, 2017) http://www.4kscore.com/news/study-confirms-4kscore-accurately-predicts-high-grade-prostate-cancer

2. Harvard Prostate Knowledge. Prostate Cancer Risk in African Americans. (Access November 9, 2017) http://www.harvardprostateknowledge.org/prostate-cancer-risk-in-african-americans

3. USPSTF Draft Recommendation Statement. Prostate Cancer: Screening. (Access November 9, 2017) https://www.uspreventiveservicestaskforce.org/Page/Document/draft-recommendation-statement/prostate-cancer-screening

4. Ibid.

5. The Journal of Urology. PD71-04 An Independent, Multi-Institutional, Prospective Study in the Veterans Affairs Health System Confirms 4Kscore Accurately Predicts Aggressive Prostate Cancer. (Access November 9, 2017) http://www.jurology.com/article/S0022-5347(17)34637-2/abstract