Get the Facts During Prostate Cancer Awareness Month:

Diagnostic Blood Test Detects Risk of Aggressive Prostate Cancer

Prostate cancer is one of the most common cancers found in American men, second only to skin cancer. In 2018, the American Cancer Society estimates 165,000 new cases of prostate cancer will be diagnosed, and 29,500 men will die from the disease. [1] Because of the slow natural progression of prostate cancer, almost all men diagnosed early with localized cancer have excellent outcomes. [2] In recent years, new research has shown the value and utility of new diagnostic testing tools incorporating novel biomarker after an abnormal PSA or digital rectal examination (DRE). This process helps to improve early detection of prostate cancer and reduce avoidable biopsies in low risk men.

How Does Prostate Cancer Start?

Prostate cancer begins with malignant cells growing in the prostate gland, where they may remain contained or spread through metastasis to the rest of the body.  Slow-growing prostate cancer is considered “indolent,” and is likely to remain contained within the prostate without active treatment. Most prostate cancers are indolent, and men with this type of disease are likely to live normal lives without therapy, monitored with conservative surveillance of the cancer.

Aggressive prostate cancer is the disease type where cancer cells spread quickly from the prostate gland to distant tissues and organs in the body, posing a serious risk to health and longevity. Aggressive prostate cancer presents a significant health risk for men, and early diagnosis is the key to effective treatment.  Prostate cancers that are diagnosed in the local stage, while still within the prostate, have a near 100% 5-year survival rate, which is reduced to 30% if the cancer is found in the distant stage (once the cancer has metastasized). [2]

For decades, physicians have used the prostate-specific antigen (PSA) test as the initial screening test for abnormal prostate activity after informed discussion with men over 40 to 50 years of age. An abnormal PSA result is often followed by a prostate biopsy: a surgical procedure taking multiple tissue cores from the prostate for examination. The prostate biopsy remains the definitive test to diagnose prostate cancer.

This PSA screening process has resulted in important patient gains. In the last generation, screening and therapy improvements have lowered the risk of dying from prostate cancer by over 50 percent [3]. However, because of PSA testing’s low specificity for aggressive prostate cancer, it has also been associated with an increase in unnecessary prostate biopsies (which can lead to complications like pain, bleeding and hospitalization). Most men who get a prostate biopsy will not have aggressive cancer. [4] PSA testing has also resulted in overtreatment of men with indolent (non-life-threatening) prostate cancer, where an unnecessary removal of the prostate was performed, which can lead to significant and permanent loss of function.

Physicians needed a smarter and better way to evaluate risk for aggressive prostate cancer, so the focus shifted to using precision biomarkers like 4Kscore.   This allows for avoiding prostate biopsies in low risk men, while helping in early diagnosis of aggressive cancers in higher risk men.

OPKO Health (Miami, FL) developed the 4Kscore Test in collaboration with leading researchers at Memorial Sloan Kettering Cancer Institute, as a follow-up test to an abnormal PSA or DRE. The 4Kscore test measures four blood biomarkers, and combines them with important clinical information (age, biopsy history and optional DRE) to provide an individual man’s risk of aggressive prostate cancer.

Research Supports Use of the 4Kscore Test

Developed in conjunction with leading cancer research centers around the world, the 4Kscore test has been extensively researched in over 15 peer-reviewed publications with over 23,000 study subjects, including two large prospective U.S. validation studies.

In 2018, in a large observational study completed in a male patient population from Malmo, Sweden, the 4Kscore Test was shown to accurately categorize risk of prostate cancer mortality in men up to 20 years after the test result. [5] A similar study in Vasterbotten, Sweden showed 4Kscore also categorized risk of metastatic cancer up to 15 to 20 years after the test. [6]

Two prospective studies validated the 4Kscore Test’s accuracy in predicting the risk of aggressive prostate cancer at biopsy. [4,7] These results indicate that using the 4Kscore Test can reduce prostate biopsy rates and overdiagnosis of indolent disease, while still accurately identifying men at higher risk for aggressive cancer for further evaluation and potential treatment. Because of the vast amount of research attesting to the 4Kscore Test’s accuracy in predicting aggressive prostate cancer risk, it is included in current U.S. and European prostate cancer early detection guidelines.

Learn More About Non-Invasive 4Kscore Testing

While prostate cancer remains one of the leading causes of cancer death in U.S. men, a better understanding of the disease, along with new diagnostic tools and therapy options, gives men at risk the opportunity to live healthy, active lives. The 4Kscore Test provides men with a personalized risk for aggressive prostate cancer so they can make informed prostate biopsy decisions—and possibly avoid an unnecessary invasive procedure.

The 4Kscore Test is offered by physicians nationwide and performed exclusively through OPKO Health’s wholly owned reference laboratory, BioReference Laboratories, Inc.  For more information about the 4Kscore Test, visit our website.



  1. American Cancer Society. “About Prostate Cancer.” Accessed 9/12/2018.
  2. American Cancer Society. “Survival Rates for Prostate Cancer.” Accessed 9/12/2018.
  3. Centers for Disease Control and Prevention. “United States Cancer Statistics: Data Visualizations”. Accessed 9/12/2018.
  4. Parekh DJ, Punnen S, Sjoberg DD, et al. A multi-institutional prospective trial in the USA confirms that the 4Kscore accurately identifies men with high-grade prostate cancer. Eur Urol 2014; 68:462-70.
  5. Sjoberg DD, Vickers AJ, Assel M, et al. Twenty-year risk of prostate cancer death by midlife prostate-specific antigen and a panel of four kallikrein markers in a large population-based cohort of healthy men. Eur Urol (2018), https://doi. org/10.1016/j.eururo.2018.02.016.
  6. Stattin P, Vickers AJ, Sjoberg DD et al. Improving the specificity of screening for lethal prostate cancer using prostate-specific antigen and a panel of kallikrein markers: a nested case-control study. Eur Urol. 2015 Aug; 68(2):207-13.
  7. Punnen S, Freedland SJ, Polascik TJ, et al. A multi-institutional prospective trial in the Veterans Affairs Health System confirms the 4Kscore maintains its predictive value among African American men. J Urology (2018), doi: 10.1016/j.juro.2017.11.113.