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MLH1: Cancer Risks

People with a mutation in the MLH1 gene have Lynch syndrome and an increased risk for several types of cancer. Learn about these cancer risks. Stay up to date by signing up for our community newsletter.

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Cancer Risk Associated with Inherited Mutations

People with an mutation have . mutations increase the risk for colorectal, endometrial and other types of cancer listed in the table below.

Experts at the National Comprehensive Cancer Network (NCCN) created guidelines which estimate the cancer risks for people with mutations. These cancer risk estimates are updated based on the latest research.

It is important to note that cancer risks are estimates over the course of a person's lifetime. Your lifetime risk and risk over the next five years will vary depending on your:

current age.
sex assigned at birth.
specific mutation.
personal and family health history.
diet, exercise, lifestyle and other factors.

If you or a relative have tested positive for an mutation, we recommend speaking with a genetics expert. They can look at your personal and family medical history to help you understand and decide on a plan for managing your risk.

Cancer risk table

Cancer Type	Lifetime Risk with Mutation	Lifetime Risk in General Population	Average Age of Diagnosis with Mutation	Average Age of Diagnosis in General Population
Colorectal	46 - 61%	4%	44 years	68 - 72 years
Endometrial	34 - 54%	3.1%	49 years	60 years
Ovarian	4 - 20%	1.1%	46 years	63 years
Kidney/ureter	up to 5%	1.8%	59 - 60 years	Not specified
	up to 13.8%	12.8%	63 years	66 years
Bladder	up to 7%	2.2%	59 years	73 years
Gastric	5 - 7%	0.8%	52 years	68 years
Small bowel	0.4 - 11%	0.3%	47 years	60s - 70s
Brain	0.7 - 1.7%	0.6%	No data	59 years
Biliary tract	1.9 - 3.7%	No data	50 years	70 - 72 years
Pancreatic	6.2%	1.7%	No data	71 years
Source: NCCN Guidelines: Genetic/Familiar High-Risk Assessment: Colorectal, Endometrial, Esophageal, and Gastric; v.1 2026.