MUTYH: Cancer Risks
Cancer Risks in People with Inherited MUTYH Mutations
MUTYH-associated polyposis (MAP) cancer risks
People with MAP tend to develop many in their colon and the rest of their gastrointestinal tract. MAP is linked to a very high lifetime risk for colorectal cancer, as high as 90% if the are not removed.
It is important to note that the colorectal cancer risk in MAP may happen before the development of a large number of . One study showed that nearly half of MAP patients with colorectal cancer had 10 or fewer lifetime by the time they developed colorectal cancer. For this reason it's important for people with MAP to follow recommended screening guidelines, even if they have not had a large number of in the past.
The risks listed below do not apply to people who have a mutation in only 1 copy of their MUTYH gene. See below for the specific cancer risk information for people with a single MUTYH mutation.
Cancer or Polyp Type |
Estimated Lifetime Risk (to Age 80) with an FAP Mutation |
Average Lifetime Risk for General Population |
Colon cancer without colectomy |
70% - 90% |
4.1% |
Duodenal polyposis (multiple polyps in the duodenum) |
17% - 34% |
|
Duodenum or periampullary cancer |
4% |
|
Gastric fundic gland polyps (polyps in the area of the stomach known as the fundic gland) |
11% |
|
Source: NCCN Guidelines: Genetic/Familial High-Risk Assessment: Colorectal, Endometrial, and Gastric; v1. 2 2024 |
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Other cancer risks for people with MAP
MAP may also increase the risk for the following cancers:
- stomach
- small intestine
- endometrial
- ovarian
- thyroid
- bladder
- breast
More research is needed to prove these links.
Cancer risks for people with a single MUTYH mutation
Unlike people with two MUTYH mutations, people with a mutation in only one copy of their MUTYH gene do not develop MAP. NCCN guidelines do not indicate an increased colorectal cancer risk for these individuals.