Questions & Answers
What is Epi proColon®?
Epi proColon® is a molecular, colorectal cancer screening test that detects methylated Septin 9 DNA in blood. DNA methylation of the SEPT9 gene is increased in colorectal cancer. Methylated SEPT9 DNA from tumors is shed into the bloodstream and the methylation pattern is detectable in plasma by Real-Time PCR.
Why a blood test?
A blood test is a common and accepted method of testing. A colorectal cancer screening test based on a blood draw may be acceptable to screening-eligible people who have been offered but have a history of not completing CRC screening by 2008 United States Preventive Services Task Force (USPSTF) recommended methods. Even after counseling with their healthcare provider, 1 in 3 people in the US still decline screening by tests requiring stool sample collection and shipping, or more invasive tests requiring advance preparation and sedation such as colonoscopy and sigmoidoscopy. A blood test has the potential to increase screening participation in the eligible population that is currently not screened.
Who should be screened with Epi proColon®?
Epi proColon® is indicated for average-risk people, age 50 or older, who have been offered and have a history of not completing CRC screening by tests recommended in the 2008 USPSTF guidelines. These recommended methods such as colonoscopy, sigmoidoscopy and high-sensitivity fecal occult blood tests (FIT) should be offered and declined before Epi proColon® is offered as an option for screening. Epi proColon® is not intended to replace screening tests recommended by appropriate guidelines (e.g., 2008 USPSTF guidelines).
Can Epi proColon® be used to screen or monitor patients at high-risk for colorectal cancer (CRC)?
No. The Epi proColon® test is a screening test for use in patients considered to be at average-risk for acquiring CRC.
Are there any age restrictions for the test?
The test was clinically studied in a demographically diverse group people between the ages of 50-85 who were considered to be of average-risk for colorectal cancer. CRC Guidelines generally recommend screening for all people between the ages of 50 and 75. Screening guidelines vary for people over age 75. The decision to screen people over age 75 should be made on an individualized basis in consultation with a healthcare provider.
Since this is a routine CRC screening test, how often should patients be tested?
The interval for use for Epi proColon® has not been established in clinical evaluations. A recently published microsimulation model to simulate colorectal (CRC) cancer incidence and mortality was extensively validated by comparison of predicted CRC incidence and mortality, adenoma dwell times, overall dwell times and lifetime risk of developing CRC with results from two large randomized controlled trials and those of the National Cancer Institute’s Cancer Intervention and Surveillance Modeling Network (CISNET) models. Based on the findings of this model, the benefits to harms ratio of annual vs two- and three-year intervals for the blood test were calculated and an annual interval resulted as the optimal screening strategy for Epi proColon®.
What should a patient do if Epi proColon® is positive?
A positive test means that methylated Septin 9 DNA has been detected in the plasma sample tested. Methylated Septin 9 has been associated with the occurrence of colorectal cancer. Because Epi proColon® is not a confirmatory test for the presence of colorectal cancer, people with a positive Epi proColon® result should be counseled by their healthcare provider to undergo diagnostic colonoscopy to confirm a positive test.
What should a patient do if Epi proColon® is negative?
A negative blood test result indicates the absence of methylated Septin 9 DNA in the plasma sample tested. Because a negative test result is not confirmatory for the absence of colorectal cancer, persons should be advised to continue participating in a recommended screening program according to screening guidelines.
Colorectal Cancer & Screening
Why should a person be screened for colorectal cancer?
Colorectal cancer is one of the most preventable and treatable cancers when it is found early. Based on the results of very large clinical trials, screening has been shown to reduce the mortality and incidence of colorectal cancer. Early stages of CRC are usually asymptomatic and therefore, early detection by screening can result in a greatly improved 5-year rate of survival and a more likely cure.
What are the recommended screening methods?
There are a number of screening guidelines that make recommendations for screening and which tests to use. The USPSTF recommends a number of tests for CRC screening with colonoscopy (every 10 years) and high-sensitivity fecal occult blood testing (FIT test, annually) being the most common.
The Epi proColon® Test – Background
What biomarkers are in the Epi proColon® test?
Epi proColon® is a test based on the detection of DNA methylation in a specific sequence of a promoter region of the SEPT9 gene. Epi proColon® also measures an internal control gene (Actin beta) to ensure that the total DNA amount in the sample is sufficient to interpret the test.
What is DNA methylation?
DNA methylation is a natural biological process where the cytosine base of DNA is modified by the addition of a methyl group. This modification is associated with the regulation of gene expression. Changes in DNA methylation often occur in cancer and can serve as a biomarker for finding cancer.
Can I use serum instead of plasma?
No. Epi proColon® was developed using plasma obtained from only BD Vacutainer® K2EDTA (lavender cap) blood collection tubes with a minimum of 3.5 mL needed to perform the test. While there are many publications describing DNA in serum, serum has not been evaluated for use with this test. Only BD Vacutainer® K2EDTA collection tubes have been validated for use with Epi proColon®.
What is cell-free circulating DNA?
Cell-free circulating DNA is the fraction of DNA that occurs in blood plasma (bloodstream).
Blood Collecting and Processing
What are the blood tube options for collecting blood specimens?
Blood should be collected according to your laboratory’s procedure for venipuncture using ONLY BD Vacutainer® K2EDTA (lavender cap) blood collection tubes. Other manufacturer’s EDTA tubes have not been validated for use with Epi proColon®.
How much blood should be collected?
Epi proColon® requires a minimum of 3.5 mL of cell-free plasma. To obtain this amount of plasma, we recommend that you collect a full 10 mL tube of blood—ensure that the evacuated tube is allowed to complete the fill volume. Some blood draw stations collect a second BD Vacutainer® K2EDTA (purple cap) blood collection tube as a backup measure.
Note: Do not freeze whole blood samples.
Are there specific plasma preparation requirements?
Plasma preparation should be performed within 4 hours after drawing blood. Whole blood collected in Vacutainer® K2EDTA (purple cap) blood collection tubes may be stored at 2°- 30°C prior to plasma preparation.
How should the plasma be stored and transported?
The plasma sample may be stored refrigerated, at 2°C to 8°C for up to 72 hours, or frozen, at -15°C to -25°C for up to 14 days. Transport and shipment of refrigerated or frozen plasma should follow the same temperature and time requirements as stated above.