Adenomatous Polyposis Colon Cancer Syndromes

Approximately two percent of all colon cancer is thought to be caused by one of three adenomatous polyposis conditions:

  • Familial adenomatous polyposis
  • Attenuated familial adenomatous polyposis
  • MYH-associated polyposis

Classic familial adenomatous polyposis (FAP) and attenuated familial adenomatous polyposis (AFAP) are due to mutations in the adenomatous polyposis coli (APC) gene. It is important to note that approximately 20 to 30 percent of FAP cases are caused by new mutations, meaning that an APC mutation may be present in an individual, even if it is absent in both parents.

MYH-associated polyposis (MAP) is caused by mutations in the mutY homolog (MYH) gene, which plays an important role in DNA repair. Individuals with MAP have mutations in both of their MYH genes, one from each parent, and they often have no family history of colon cancer or polyps in their parents (although siblings may be affected).

Since individuals with a polyposis syndrome often do not have a family history of colorectal polyps or cancer, genetic testing is the only way to identify people who are truly at risk.

What is COLARIS AP® Testing?

Myriad Genetics offers genetic testing to determine whether you are a carrier of a gene mutation associated with a polyposis syndrome. In order to assess your risk of carrying one of these mutations, your healthcare professional may ask you questions about your personal and family medical history. If you are identified as being at increased risk for a polyposis syndrome, genetic testing provides the most accurate way to determine your risk of developing cancer.

COLARIS AP® testing does not tell you whether you have cancer, but detects mutations in the APC and MYH genes. These are the gene mutations that are associated with Adenomatous Polyposis Colon Cancer Syndrome.

Is COLARIS AP® testing suitable for me?

COLARIS AP® is for individuals at risk for adenomatous polyposis colon cancer. If you and your doctor determine that you may be at risk for adenomatous polyposis colon cancer, COLARIS AP® is right for you.

Identifying people who are at risk for adenomatous polyposis syndromes and monitoring them is perhaps the most critical step in changing hereditary cancer outcomes. In order to assess your risk of carrying a mutation in the APC or MYH genes, your healthcare professional may ask you questions about your personal and family medical history. Genetic testing for a polyposis syndrome should be considered if:

  • You have multiple colorectal adenomas (usually 10 or more cumulative adenomas)
  • You are a relative of an APC or MYH mutation carrier

Myriad Genetics’ Hereditary Cancer Quiz helps you to assess whether you might be a good candidate for testing. This quiz can help you get the information you need to discuss your risk of cancer with your healthcare provider and ask for further evaluation. If you take the quiz and find red flags in your own history or your family history, you may benefit from hereditary cancer testing.

The quiz will help you determine if you are at risk for the following hereditary cancers:

  • Breast Cancer
  • Ovarian Cancer
  • Colon Cancer
  • Uterine Cancer
  • Pancreatic Cancer

To begin the process of seeing if genetic testing is right for you, check out Myriad’s Hereditary Cancer Quiz:

How can COLARIS AP® help me manage my condition?

Knowing if you have a gene mutation can help you know your risk of hereditary cancer and inform your family of their potential risk of hereditary cancer.

The COLARIS AP® test results may enable you and your family to make more informed choices and help you to be ready against hereditary cancer. They can also help your doctor manage your healthcare needs more effectively.

If the COLARIS AP® test confirms the presence of an APC or MYH gene mutation, your healthcare professional may choose among the following medical management options to help reduce cancer risk and either delay the onset of cancer or detect it at an earlier, more treatable stage:

  • Counseling for mutation carriers and their family members on the underlying cause of the cancer or adenomas.
  • Increased surveillance and other interventions specifically intended for individuals with the APC or MYH gene mutations.
  • Improved compliance with tailored screening recommendations and preventive measures.
  • Significantly improved colon cancer survival rates and reduced medical costs through early diagnosis and treatment of cancer, should it develop.

What is the unique advantage of Myriad COLARIS AP® testing?

No company has more experience in genetic testing for hereditary cancer than Myriad. Over the last 20 years, Myriad has delivered more than one million test results. Myriad has the lowest Variant of Uncertain Significance (VUS) rate globally with a <3% VUS rate (0.6% for BRCA1 mutations). A lower VUS rate means a lower chance of getting an uncertain result, which means more confidence and clarity in your results.


[accordion][accordion-item title=”I already know I have a family history of cancer. Why should I get tested?”]Testing for a hereditary cancer risk helps you and your healthcare professional understand your risk so you can make the best choices for preventive care. Knowing your family history is an important first step, but testing can give you a more accurate picture of your risk. [/accordion-item][accordion-item title=”I already have cancer. Why should I get tested?”]Testing for a hereditary cancer helps you and your healthcare professional understand your risk for developing a second primary cancer. This information can allow you to make the best choices for preventive care. [/accordion-item][accordion-item title=”Is testing recommended for everyone?”]While testing is the most accurate way to determine the risk of hereditary cancer, only people who have cancer in their family or a personal history of the disease need to be tested. If you have had cancer and/or cancer runs in your family, let your healthcare professional know. To help you assess whether you may benefit from hereditary cancer genetic testing, take the Myriad Hereditary Cancer Quiz. This simple, 30-second quiz can help you get the information you need to discuss your risk of cancer with your healthcare professional and ask for further evaluation.[/accordion-item][accordion-item title=”How do I get tested?”]Speak to your doctor. Once your doctor orders a test for you from us, we will take care of the rest. The clinic will take a small blood sample and send it to the lab for testing. The lab cannot accept a test directly from you, as a doctor first needs to assess whether or not the test is right for you. Once the testing is completed, a report will be sent to your doctor who will then go through and explain your results to you, and suggest the next steps.[/accordion-item][accordion-item title=”Can I use any other sample collection kit that is not provided by Myriad?”]No! Our processes have been optimized and validated with the kits we provide. [/accordion-item][accordion-item title=”Which completed forms must accompany my sample?”]The clinic will help you complete and sign an Informed Consent Form. This form will be submitted with the sample. The consent form will be used to match your sample to the test request submitted by the doctor, and is needed to let the lab know that you have agreed to send your sample for the test. Samples received without these forms cannot be processed, as your consent is required to test your sample. [/accordion-item][accordion-item title=”Who will receive the test results?”]Myriad will provide your test report to the healthcare professional who ordered the test. [/accordion-item][accordion-item title=”Why are the results of testing sent directly to the ordering healthcare professional rather than the patient or parent of a patient?”]Results are sent to the ordering healthcare professional as they would need to discuss the results, result interpretation, treatment management, and any follow-up testing with you.[/accordion-item][/accordion]