Lynch Syndrome and HNPCC: Symptoms, Testing and Screening
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Lynch syndrome is an inherited genetic condition that increases the risk of developing cancer. People with Lynch syndrome are more likely to develop cancer before age 50 and should undergo lifelong cancer screenings to help detect and treat cancer early. [1]
If you have Lynch syndrome, a family history that may suggest inherited cancer risk, or symptoms such as blood in the stool, speak with a qualified healthcare provider about evaluation, genetic counseling and appropriate screening.
Medical note: This article is educational and does not diagnose or treat an individual. A qualified clinician or genetic counselor should confirm any diagnosis, testing plan or treatment decision.
Quick Answer
Lynch syndrome is an inherited condition that raises the risk of several cancers, often at younger ages. It happens when a mismatch-repair gene cannot properly fix changes in DNA. One parent can pass the altered gene to a child, although some mutations occur randomly without a family history. [1]
What the research says
Cancer risk and deaths in Lynch syndrome extend beyond the colon. In a prospective database of 8,500 carriers from 25 countries (71,713 years of follow-up), more deaths followed non-colorectal Lynch syndrome cancers than colorectal cancers among carriers having colonoscopy surveillance. Estimated mortality up to age 75 was 8% for endometrial, 13% for colon and 15% for ovarian cancer, compared with 83% for pancreatic and 66% for brain cancer (Dominguez-Valentin et al., EClinicalMedicine, 2023). [2]
Regular colonoscopy appears to find colorectal cancer at an early stage. In a prospective New Zealand cohort of 381 people with Lynch syndrome offered annual colonoscopy (2,061 colonoscopies over 2,296 person-years), 18 developed colorectal cancer; 94% were stage 0–II and there was no colorectal cancer–related death. This was an observational study without a comparison group (Lamba et al., Clin Gastroenterol Hepatol, 2020). [3]
What is Lynch syndrome?
Lynch syndrome is a genetic condition that increases the risk of developing cancer. People diagnosed with it are more likely to develop cancer before age 50. The condition is also associated with the term hereditary non-polyposis colorectal cancer, or HNPCC. [1]
Lynch syndrome can affect anyone because genetic mutations may pass from a parent to a child during fetal development, and mutations can sometimes occur randomly without being present in the family history. [1]
How common is Lynch syndrome?
Lynch syndrome occurs in approximately one in 279 people in the United States. It is estimated to contribute to about 4,000 colorectal cancer cases and 1,800 uterine or endometrial cancer cases each year. [1]
What causes Lynch syndrome?
Lynch syndrome results from a genetic mutation in one of five genes responsible for repairing errors in DNA. These are called mismatch-repair genes. The genes associated with Lynch syndrome are MLH1, MSH2, MSH6, PMS2 and EPCAM. [1]
When the mismatch-repair gene does not have all the instructions needed to remove damaged cells, those cells can build up in tissues and cause cancer.
Gene | What it represents in this guide |
MLH1 | |
One of the five genes associated with Lynch syndrome | |
MSH2 | |
One of the five genes associated with Lynch syndrome | |
MSH6 | |
One of the five genes associated with Lynch syndrome | |
PMS2 | |
One of the five genes associated with Lynch syndrome | |
EPCAM | |
One of the five genes associated with Lynch syndrome |
How is Lynch syndrome inherited?
Lynch syndrome is an autosomal dominant condition. This means that only one parent needs to carry and pass the mutated gene to a child for the child to inherit the condition. [1]
People diagnosed with Lynch syndrome should tell family members and encourage them to seek genetic counseling. Genetic counseling can help a family understand the risks of having a child with a genetic condition and can include an evaluation of personal and family history plus genetic testing for the familial mutation. [1]
What cancers are associated with Lynch syndrome?
Lynch syndrome can lead to cancers affecting several organs. The specific organs at risk depend on which gene has the mutation.
Cancer type or organ | Relationship to Lynch syndrome |
Colon and rectum | The most common cancer associated with Lynch syndrome |
Uterus or endometrium | A cancer associated with Lynch syndrome |
Ovaries | A cancer associated with Lynch syndrome |
Stomach and small intestine | Cancers associated with Lynch syndrome |
Upper urinary tract | A cancer associated with Lynch syndrome |
Pancreas, liver and gallbladder | Cancers associated with Lynch syndrome |
Prostate | A cancer associated with Lynch syndrome |
Skin and brain | Cancers associated with Lynch syndrome |
Colon cancers related to Lynch syndrome tend to be more common on the right side of the colon and may develop faster than in the general population—about one to two years compared with 10 years. To learn more about this cancer, read our guide to colon cancer. [1]
People who develop colorectal cancer because of Lynch syndrome also have a higher risk of developing it again. The recurrence risk described is approximately 15% within 10 years after surgery for the first cancer, 40% within 20 years and 60% after 30 years. [1]
What are the symptoms of Lynch syndrome?
Symptoms vary from person to person and may reflect the cancers associated with the condition. Not everyone has symptoms before cancer becomes advanced.
Common symptoms related to colorectal cancer include blood in the stool, constipation, abdominal pain or cramps, diarrhea, stool that is smaller than normal, fatigue, feeling full or bloated, nausea and vomiting. [1]
Possible symptom | What it may involve |
Blood in stool | Blood noticed when passing stool |
Bowel changes | Constipation, diarrhea or smaller-than-normal stool |
Abdominal symptoms | Pain or cramps, feeling full or bloated |
General symptoms | Fatigue |
Digestive symptoms | Nausea or vomiting |
If you have any of these symptoms, contact a qualified healthcare provider. Symptoms can have causes other than cancer, but they should not be ignored.
How is Lynch syndrome diagnosed?
Genetic testing can diagnose Lynch syndrome by checking whether a mutation is present in the family. Testing may involve a blood draw or a brushing from inside the mouth, called a buccal swab. [1]
Testing looks for mutations in MLH1, MSH2, MSH6, PMS2 or EPCAM. If testing identifies a mutation, a healthcare provider confirms the diagnosis. Prenatal screening and genetic testing may also be used before birth, and genetic tests can help diagnose a child after birth. [1]
Evaluation | What it may involve |
Genetic counseling | Review of personal and family history and discussion of inherited-risk questions |
Blood-based genetic testing | A blood draw to check for a relevant gene mutation |
Buccal-swab testing | A brushing from inside the mouth to check for a relevant gene mutation |
Prenatal screening | Screening and testing offered before a baby is born |
Postnatal testing | Genetic testing that can help diagnose a child after birth |
What screening tests are used with Lynch syndrome?
After a Lynch syndrome diagnosis, a provider may recommend regular testing to look for associated cancers. Screening schedules should be individualized by a qualified care team. The intervals below are those described in the clinical overview.
Screening or test | Purpose and interval described |
Colonoscopy | Examines the large intestine, colon and rectum; recommended every one to two years |
Transvaginal ultrasound | Examines the ovaries and uterus; recommended every one to two years |
Urinalysis | Screens for renal tumors and related complications; ordered annually |
Tumor biopsy | Examines cells from a growth when cancer is suspected |
Upper endoscopy or capsule endoscopy | Looks for stomach and small-bowel cancer; scheduled every three to five years |
Can Lynch syndrome cause colon polyps?
People with Lynch syndrome may develop a few colorectal polyps called adenomas. These are noncancerous tumors. If they are not found and removed, they could become cancer. Regular colonoscopies help detect and remove these polyps. [1]
How is Lynch syndrome treated?
Treatment focuses on detecting cancer and surgically removing it from the body. Because Lynch syndrome can affect multiple organ systems, care may involve several types of clinicians, including gastroenterologists, surgeons, gynecologic oncologists, urologists, dermatologists, gynecologists, primary care physicians, geneticists, genetic counselors and oncologists. [1]
Some people with Lynch syndrome choose to have a hysterectomy, which removes the uterus; an oophorectomy, which removes both ovaries; or a colectomy, which is bowel-resection surgery, because they have an increased risk of cancer in certain organs. These are significant medical decisions that require individualized discussion with a qualified care team. [1]
Can cancer return after treatment?
Yes. Cancer can return even after it has been surgically removed. Because Lynch syndrome continues to increase cancer risk, ongoing follow-up and regular screening remain important after treatment. [1]
What is the outlook for Lynch syndrome?
Lynch syndrome itself has no cure, and its outlook depends on whether cancer develops and how early any cancer is found. The best prognosis occurs when a provider finds and removes cancer early, before it spreads to other parts of the body. Lifelong cancer screening, including regular colonoscopy, is highly recommended for people diagnosed with Lynch syndrome. [1]
The outlook is different for every person and depends on whether cancer develops, the cancer type, how early it is found and the care plan recommended by the clinical team.
Can Lynch syndrome be prevented?
Lynch syndrome cannot be prevented because it is an inherited condition. However, people with Lynch syndrome can follow lifelong cancer-screening plans beginning in adulthood to help detect cancer early. [1]
When should you see a healthcare provider?
If you have Lynch syndrome, schedule annual checkups and work with your provider to plan regular screening tests. Contact a provider promptly if you notice a lump, growth or change in your skin that could be a sign of cancer. [1]
If you have symptoms such as blood in the stool, bowel changes, abdominal pain, fatigue, bloating, nausea or vomiting, arrange an evaluation rather than trying to determine the cause yourself.
Lynch syndrome and HNPCC: are they the same?
Lynch syndrome and HNPCC can identify the same condition, but the terms differ slightly in how inheritance is described. Lynch syndrome can result from a mismatch-repair gene mutation that occurs randomly, without a family history. HNPCC is described as always resulting from family inheritance. [1]
Conclusion: lifelong screening is central to Lynch syndrome care
Lynch syndrome is an inherited condition caused by a mutation in one of five mismatch-repair genes. It can raise the risk of colorectal, uterine, ovarian, stomach, small-intestine, urinary-tract and other cancers, often at younger ages.
Genetic counseling, genetic testing and lifelong screening can help identify cancer early. Care may include a multidisciplinary team, surgery when cancer is found, and regular follow-up because cancer can return.
If Lynch syndrome runs in your family, you have symptoms or you have questions about testing, contact a qualified healthcare provider or genetic counselor. Rinnit.com is here to make complex health information easier to understand.
Frequently Asked Questions
What does Lynch syndrome mean?
Lynch syndrome is a genetic condition that increases the risk of developing several cancers, often before age 50.
What genes cause Lynch syndrome?
Lynch syndrome is associated with mutations in the mismatch-repair genes MLH1, MSH2, MSH6, PMS2 and EPCAM.
Is Lynch syndrome inherited?
Yes. It is an autosomal dominant condition, meaning one parent needs to carry and pass the mutated gene to a child for the child to inherit it. Some mutations can also occur randomly without a family history.
Is Lynch syndrome the same as HNPCC?
The terms can identify the same condition, but there is a slight difference in inheritance: Lynch syndrome may result from a random mutation, while HNPCC is described as always resulting from family inheritance.
What cancers are linked to Lynch syndrome?
Associated cancers include colorectal, uterine or endometrial, ovarian, stomach, small-intestine, upper urinary tract, pancreatic, liver, gallbladder, prostate, skin and brain cancers.
What are the symptoms of Lynch syndrome?
Symptoms may include blood in the stool, constipation, abdominal pain or cramps, diarrhea, smaller-than-normal stool, fatigue, bloating, nausea or vomiting. Not everyone has symptoms before cancer becomes advanced.
How is Lynch syndrome tested?
Genetic testing may use a blood draw or buccal swab to look for a mutation in one of the five genes associated with Lynch syndrome. Genetic counseling can help explain the testing process and family implications.
How often should people with Lynch syndrome be screened?
The clinical overview describes colonoscopy every one to two years, transvaginal ultrasound every one to two years, annual urinalysis and upper or capsule endoscopy every three to five years. A qualified care team should confirm an individual screening schedule.
Can Lynch syndrome be cured?
There is currently no cure for Lynch syndrome itself. Early detection and treatment of associated cancers can improve the prognosis, and lifelong screening is recommended.
When should I see a provider?
People with Lynch syndrome should attend annual checkups and follow a regular screening plan. Seek prompt care for lumps, growths or skin changes, and arrange an evaluation for symptoms such as blood in the stool or persistent bowel changes.
Related Reading
Genetic Testing (DNA Tests): Types, Uses, Risks and What Results Mean explains the DNA tests that can confirm this condition or show carrier status.
References
Cleveland Clinic. Lynch Syndrome: Signs/Symptoms, Causes, Outlook. Cleveland Clinic. Last updated September 12, 2022. https://my.clevelandclinic.org/health/diseases/17195-lynch-syndrome-and-hnpcc
Dominguez-Valentin M, Haupt S, Seppälä TT, et al. Mortality by age, gene and gender in carriers of pathogenic mismatch repair gene variants receiving surveillance for early cancer diagnosis and treatment: a report from the prospective Lynch syndrome database. EClinicalMedicine. 2023;58:101909. PMID 37181409. https://doi.org/10.1016/j.eclinm.2023.101909
Lamba M, Wakeman C, Ebel R, et al. Associations between mutations in MSH6 and PMS2 and risk of surveillance-detected colorectal cancer. Clin Gastroenterol Hepatol. 2020;18(12):2768-2774. PMID 32240831. https://doi.org/10.1016/j.cgh.2020.03.048
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare professional with any questions about a medical condition or treatment.
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