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Beyond BRCA: MUTYH-Associated Polyposis (MAP)

Last Updated:  January 8, 2019

This article is part of a series built to highlight rare hereditary cancer syndromes. Here’s one woman’s story of living with MUTYH-Associated polyposis (MAP).

Genetic Counseling Note: MUTYH is a cancer predisposition gene that is associated with MAP. Unlike most hereditary cancer syndromes, MAP is inherited in an autosomal recessive pattern.  This means that in order to have MAP, a person needs to have a mutation (also known as a pathogenic variant) in both copies of the MUTYH gene– one mutation is usually inherited from the mother, and the other from the father.  Because of this inheritance pattern, people with MAP often have parents who do not have the condition, but may have siblings with the condition.

People with MAP have an increased risk to develop colon polyps (mainly adenomas, but other types can be seen) and colon cancer (43-100%), if those polyps are not removed in a timely manner.  Duodenal adenomas (17-25%) and duodenal cancer (4%) can also be seen in MAP.  MAP may cause increased risk for other cancers as well, including endometrial cancer, but these associations must be studied further for confirmation.

People with one MUTYH mutation do not have MAP but may have a modestly to moderately increased risk of colorectal cancer.

For more on MAP, check out https://www.ncbi.nlm.nih.gov/books/NBK107219/ and https://ghr.nlm.nih.gov/gene/MUTYH#conditions.

Tell us a little about yourself:

I’m 64 years old and am a retired nurse. I enjoy going for walks, taking occasional rides on my bike (a special bike for people who’ve had hip replacements), and doing jigsaw puzzles.  We recently renovated our kitchen, and I love to cook, try new recipes, and have family parties.  I also feel very fortunate that I’m here to help my elderly parents and be here for my husband and children.

Tell us about your personal history

At age 48, I was found to have an unknown primary type of Stage 4 cancer in my femur. They eventually determined that I had both cervical and endometrial cancers, with the cervical cancer having spread to the femur.  I knew that my situation was very serious, and my son and daughter were only 18 and 15 at the time.  My treatment included radiation, chemotherapy, and then surgery. I’ve had additional treatments and procedures since then, but I’m here 15 years later and cancer free since 2003!

Did you have a family history of cancer?

My brother, my only sibling, had rectal bleeding in his twenties.  This led him to have a colonoscopy, and he found that he had polyposis, meaning many colon polyps.  Based on his history, I decided to have an early colonoscopy myself and was also found to have many polyps. Tragically, my brother stopped going for colonoscopies because he owned his own business and was really busy. Seven years went by before my brother finally had another colonoscopy, at which time he was diagnosed with colon cancer that had metastasized to the liver.  My brother, sadly, died of colon cancer at age 47.

What made you go for genetic counseling?

I first went for genetic counseling in 2002 on the recommendation of my doctor.  My genetic counselor, Ellen Matloff, initially suspected FAP or Lynch syndrome based on my personal and family history of cancer.  I had genetic testing for both, and both were negative.  We sent my DNA off to a research study in London and never received an answer back.

So, initial testing was not successful in finding the genetic cause in your family.  Was that frustrating?

It was frustrating, but I was mostly disappointed.  I wanted to know why my brother and I had developed cancer and polyps at young ages, and we didn’t find the answer.  I kept in touch with my genetic counselor periodically. In 2011, we ordered a larger panel that included many genes, and I finally got an answer – I carry 2 mutations in a gene called MUTYH.  I was so relieved!  We believe my endometrial cancer may be linked to MAP, although a clear association between MAP and endometrial cancer is still being researched.  However, these findings certainly explain my history of colon polyps and my brother’s history of colon polyps and cancer.  I felt empowered by the knowledge that now my condition had a name.

What advice do you have for others diagnosed with metastatic cancer?

Stay away from the statistics.  If you google the statistics on your survival, it will make you crazy. No matter what you hear, don’t give up hope. There are exciting things going on in cancer research and treatment.  Metastatic cancer used to be a death sentence for many, but it’s not anymore – advocate for yourself.  I was in a better position than many people because I’m a nurse, and I had worked at an insurance company.  I knew how to navigate the system.  If you don’t have that experience, find someone to navigate for you. Find a doctor that you trust and develop a rapport with him/her.

What message do you have for people who have a striking personal and family history of cancer or polyposis, in whom no genetic cause has been found (uninformatives)?

Touch base with your genetic counselor on a yearly basis because there are new tests being developed all of the time.  Don’t give up.  If you and your genetic counselor agree that you are at increased risk to develop cancer, even after genetic testing is negative, do all of the screenings that are recommended. Err on the side of caution.  Look at my brother – he lost his life because he didn’t keep up with his colonoscopies.  It’s tragic.  I’m determined that I won’t have the same fate – and if I do, it won’t be because I didn’t take advantage of the treatments and recommendations that were available to me.

Photo by solarisgirl, via Flickr.