How is the COLARIS AP test performed?
A small amount of blood is drawn from the patient and sent to Myriad Genetics for DNA sequencing analysis of the APC and MYH genes. COLARIS AP can also detect large rearrangements in the APC gene that will not be identified by gene sequencing.
How long does it take for COLARIS AP test results?
Results take up to 21 days and are sent to the provider identified as “mail to” on the Test Request Form.
If a patient has already been diagnosed with FAP or AFAP, what does a positive COLARIS AP result indicate?
Individuals with an APC mutation are at a greater risk for developing a new cancer – even extracolonic cancer following a prophylactic colectomy. Knowing a patient’s genetic status can help reduce this risk or detect another potential cancer at an earlier, more treatable stage. Importantly, a patient’s test results also have significant meaning for the health of his or her family members, especially since FAP is characterized by juvenile onset. In addition, patients clinically diagnosed with FAP or AFAP may have mutations in their MYH genes, leading to a condition called MAP, which presents different risks to family members. Genetic testing cane help distinguish between MAP and FAP/AFAP in certain families.
How do I manage MYH-Associated Polyposis (MAP) syndrome patients?
Medical society management recommendations for MAP include colonoscopies every 1-2 years starting at age 25-30, upper endoscopies every 3-5 years starting at age 30-35, and surgical considerations. The most appropriate medical management will vary based upon your patient’s clinical presentation. For medical management references,visit References.
How do I manage patients who received a single MYH mutation result?
Medical management should be determined by clinical findings and personal and family history of colorectal polyps and/or cancer. Current data are limited but suggest that any increase in risk, if present, is likely to be small (N Engl J Med 2003;348:791-799; Lancet 2003;362:39-41; J Natl Cancer Inst 2004;96:1631-1634).