Emerging Bio Markers for Prostate Cancer Detection

The PCA3 is a new gene-based test to aid in the diagnosis of prostate cancer. This is great news in this field because there aren't that many screening tests for prostate cancer, a.k.a the silent killer. 

How PCA3 Test Works

The PCA3 is a fairly simple test. A urine sample is collected following a DRE (digital rectal exam) for determination of the PCA3 score. Specific for prostate cancer and, unlike the PSA, the test is not affected by prostate enlargement or other non-cancerous prostate conditions

The PCA3 score, in addition to a DRE and PSA test, provides useful information to help decide if a biopsy is needed, or can be delayed

If you have a positive biopsy, the PCA3 score may give additional information about the aggressiveness of the cancer and it may help in deciding which treatment is appropriate

Prostate Health Index (PHI):

Many researchers in the field are claiming that it gives us as doctors more accurate information on what an elevated PSA level might mean and the probability of finding cancer on a biopsy.

The PHI measures PSA, free PSA, p2PSA – all three are combined in an algorithm and give a probability for prostate cancer. It's evaluated as being 3X more specific for prostate cancer than just a sole PSA test. The biggest improvement with the PHI is the specificity it gives and we've seen a substantial decrease in the number of prostate biopsies that are negative for cancer.

The PHI results are intended to be used to help distinguish between prostate cancer from benign prostatic conditions in men 50 years of age and older with total PSA results in the 4 – 10 ng/mL range and negative digital rectal examination (DRE) findings.

4K Score

This test measures four prostate-specific kallikreins in the blood: Total PSA, Free PSA, Intact PSA, and Human Kallikrein 2 (hK2). The blood test results are combined in an algorithm with patient age, digital rectal exam (nodule, no nodule), and prior negative biopsy (yes, no). The test then provides a % probability on a scales from <1% to >95% for the patient having high-grade prostate cancer. Both tests measure the variance of the PSA in the blood

The 4K Score is designed to reduce the number of unnecessary negative biopsies that detect low-grade cancer. With these tests – not all men with an elevated PSA will need biopsy.

Genetic Testing: When Is It Used

1. For Biopsy

• Oncotype DX: biopsy based genetic test that can be combined with other measures to predict aggressiveness of PCa
  
• If biopsy is positive for cancer: 2 tests
  
  • The Polaris & Genomic Prostate Score 
    
    • purpose is to distinguish between aggressive cancers that need treatment and those that are slow growing and may need active surveillance
      

2. After surgery

• Genome DX :: Decipher Prostate Cancer Test
  
• The Decipher test predicts the probability of metastasis after surgery
  
• Provides an independent assessment of tumor aggressiveness
  
• Information distinct from that provided by Gleason score or PSA.
  

Decipher is a genomic test, which means it evaluates the activity of genes in the tumor that are shown to be involved in the development and progression of prostate cancer.

• Decipher does this by measuring the expression levels of 22 RNA biomarkers involved in multiple biological pathways across the genome that are associated with aggressive prostate cancer.
  
• Uses expression of these biomarkers to calculate the probability of clinical metastasis within 5 years of radical prostatectomy surgery, and within 3 years of successive PSA rise (biochemical recurrence).
  
• Decipher analyzes a small tissue sample that was removed during surgery and is routinely archived or stored by the pathology laboratory.