Read about different genes that are linked to hereditary cancer, their associated risks and guidelines for screening, preventing and treating cancers in people with inherited mutations in these genes.
Hereditary Cancer and Genetic Testing
I am here to learn about:
Genetic Testing Lynch Syndrome I've Tested Positive, Now What? Men with Mutations Managing Menopause Women with Mutations Genetics and Prostate Cancer Genetics and Ovarian Cancer Genetics and Endometrial Cancer Genetics and Colorectal Cancer Biomarker Testing Information for Healthcare Professionals Information for Researchers Genetics and Pancreatic Cancer Genetics and Breast Cancer

Hereditary Cancer Genes and Risk > By Gene Mutation > MLH1 > Cancer Risk

1
Overview
2
Cancer Risk
3
Risk Management
4
Cancer Treatment
5
Other Considerations

Cancer risk associated with inherited MLH1 mutations

If you have tested positive for an MLH1 mutation, we recommend speaking with a genetics expert who can look at your personal and family history of cancer, and can help you decide on the best risk management plan.

MLH1 cancer risks include the following:

Risk for cancer in people with an MLH1 mutation. Source: NCCN: Genetic/Familiar High-Risk Assessment: Colorectal Version 1.2020
Cancer type Lifetime risk with for people with MLH1 mutation Lifetime risk for people in general population Average age of diagnosis for people with MLH1 mutation Average age of diagnosis for people in the general population
Colorectal 46 - 61% 4.2% 44 years 68 - 72 years
Endometrial 34 - 54% 3.1% 49 years 60 years
Ovarian 4 - 20% 1.3% 46 years 63 years
Kidney/ureter 0.2 - 5% 1.2% 59 - 60 years Not specified
Bladder 2 - 7% 2.4% 59 years 73 years
Gastric  5 - 7% 0.9% 52 years 68 years
Small bowel .4 - 11% 0.3% 47 years 60s - 70s
Brain .7 - 1.7% 0.6% No data 59 years
Biliary tract 1.9 - 3.7% 0.2% 50 years 70 - 72 years
Pancreatic 6.2% 1.6% No data 71

People with an inherited MLH1 mutation may have an increased risk for other cancers. The exact risks for the following cancers are unknown:

  • sebaceous skin growths
  • prostate cancer
  • breast cancer 

Research on how inherited mutations in the MLH1 gene affect cancer risk is ongoing.

Lifetime risk for colorectal cancer in people with <abbr data-toggle='tooltip' class='glossary-tip tt-mlh1' title='<p>MLH1&nbsp;is a gene found on chromosome 3.&nbsp;Mutations in MLH1 are associated with Lynch Syndrome. People with Lynch Syndrome have an&nbsp;increased the risk for&nbsp;colon, uterine, ovarian, pancreatic and other cancers.&nbsp;</p> <p>Also see Lynch Syndrome.&nbsp;</p> ' >MLH1</abbr> mutations     Lifetime risk for endometrial cancer in women with an <abbr data-toggle='tooltip' class='glossary-tip tt-mlh1' title='<p>MLH1&nbsp;is a gene found on chromosome 3.&nbsp;Mutations in MLH1 are associated with Lynch Syndrome. People with Lynch Syndrome have an&nbsp;increased the risk for&nbsp;colon, uterine, ovarian, pancreatic and other cancers.&nbsp;</p> <p>Also see Lynch Syndrome.&nbsp;</p> ' >MLH1</abbr> mutation     

Lifetime risk for ovarian cancer in women with <abbr data-toggle='tooltip' class='glossary-tip tt-mlh1' title='<p>MLH1&nbsp;is a gene found on chromosome 3.&nbsp;Mutations in MLH1 are associated with Lynch Syndrome. People with Lynch Syndrome have an&nbsp;increased the risk for&nbsp;colon, uterine, ovarian, pancreatic and other cancers.&nbsp;</p> <p>Also see Lynch Syndrome.&nbsp;</p> ' >MLH1</abbr> mutations     Graph of pancreatic cancer risk

clinical-trials
  • NCT00508573: Registry for Women Who Are At Risk Or May Have Lynch Syndrome. The goal of this study is to create a registry of information about women who have or are at risk for Lynch syndrome, in order to study gynecologic cancer risks.
  • The HEROIC Registry allows people with Lynch syndrome to contribute medical information and their experiences living with Lynch Syndrome and its associated cancers to help researchers develop new treatments, understand the various Lynch genetic mutations, and conduct further studies and clinical trials. The registry is maintained by the nonprofit organization AliveAndKickn.