Lynch Syndrome

Definition - What is Lynch Syndrome?

The term Lynch syndrome denotes a genetic predisposition to develop a certain form of colon cancer. This form of cancer is called hereditary (hereditary) non-polypous (Description of the morphological condition) Colon carcinoma (Colon cancer), and is often abbreviated as HNPCC. The affected people often develop this special type of colon tumor at an unusually young age, i.e. before the age of 50.

However, not everyone who has the genetic makeup of Lynch syndrome will develop colon cancer. On the other hand, other organs can also develop a tumor, since the genetic predispositions that favor the development of a tumor are present in all body cells. Regular checks and preventive examinations are therefore necessary for those affected by Lynch syndrome in order to adequately treat tumors that develop at an early stage.


Lynch syndrome is always caused by the DNA of the affected person. A change in certain genes means that certain enzymes cannot be formed correctly in the cells of the intestinal mucosa. Enzymes are proteins that are responsible for a molecular process or a biochemical reaction.

The enzymes that are incorrectly built in Lynch syndrome and therefore do not function as intended are part of the "repair mechanisms" of the body's cells: Such mechanisms correct errors in the DNA of a cell that arose during the process of cell division. Since the intestinal mucosa is one of the tissues in the body that divide relatively frequently, there is a high probability that cells with incorrect genetic information will develop here.

These, in turn, can lead to cell death mechanisms being switched off, so that the cell continues to exist beyond its intended lifetime and continues to divide. This creates uncontrolled cell division, which is the origin of cancer. In people who are affected by Lynch's syndrome, dysfunctional enzymes first lead to the formation of cells with incorrect genetic information, and as a result, the actually preprogrammed cell death does not occur. As mentioned above, the intestinal tissue is particularly at risk due to the higher rate of cell division, but with Lynch syndrome tumors can also develop in other tissues (see below).

You can read more interesting information here:

  • Is Colon Cancer Hereditary?
  • What are the causes of colon cancer?


Since Lynch syndrome is a hereditary disease, the diseases in the family are first analyzed in order to establish a diagnosis. Here, for example, it is examined whether close relatives have an already confirmed HNPCC or a tumor that could be triggered by an unsecured Lynch syndrome. If there is a familial accumulation and if certain criteria are met, the presence of a Lynch syndrome in the DNA is very likely. As a next step, a genetic analysis of the person concerned can then be carried out.

Which other tumors are common?

Lynch syndrome is a genetic predisposition. Since humans normally carry the same genetic material in all body cells, there is an increased risk of tumors not only for the intestine but also for other organs or tissues.

Tissues whose cells are designed to divide regularly are particularly at risk, for example because the tissue is regularly renewed: These include the organs of the digestive tract, i.e. stomach, esophagus and small intestine, as well as the kidneys and ureters and the liver. For the brain, people with Lynch syndrome are also at an increased risk of tumors. The ovaries can also be affected by the development of tumors, as the egg cells they contain are designed to divide. Since a tumor can develop in all of the tissues mentioned in people with Lynch syndrome, regular checks should be carried out accordingly.

Also read the article: The genetic test


Lynch syndrome is defined as a hereditary disease in the genetic information of an affected person. When (or whether) it leads to symptoms in the course of life, however, is unclear: Because Lynch syndrome does not show any abnormalities other than the development of tumors.

HNPCC should therefore always be considered, especially in the case of tumors at an unusually young age or if they are familial. However, skin tumors can be more visible than tumors on the internal organs. Since in some cases the HNPCC can be linked to the occurrence of certain types of skin cancer, the possibility of Lynch syndrome should also be considered with these skin conditions.


The treatment of a genetically present Lynch syndrome is first of all prevention. Affected people therefore have to have regular check-ups, first of the intestines, and later also of the stomach. This means that tumors that are developing can be detected early and treated accordingly quickly.

The treatment of the tumor that has developed does not differ from the treatment of other tumors in the respective area. Whether and which method of tumor therapy (surgery, radiation, drug chemotherapy) is used depends on the exact type and location of the tumor.

Read more on the topic:

  • Colon cancer therapy
  • Therapy of gastric cancer

Life expectancy and disease course

Regular checkups are crucial for the prognosis of Lynch syndrome. Ultimately, this syndrome is an increased risk for the affected person to develop a malignant tumor. As with all types of cancer, early detection and treatment therefore has a very positive effect on the course of the disease and the chances of recovery.

People with a statistically increased risk of cancer should be checked regularly for a new tumor: This means that relatives of an affected person should have a colonoscopy every year from the age of 25 and an additional gastroscopy from the age of 35. If these recommendations are followed, the course of the disease is good and life expectancy is not significantly lower than for people who are not affected by Lynch syndrome.

For more information, see Life expectancy in colon cancer.

Recommendations from the editorial team

You can find more interesting information on the subject of Lynch Syndrome at:

  • Causes of Colon Cancer
  • Is Colon Cancer Hereditary?
  • Life expectancy in colon cancer
  • What is the Typical Age for Colon Cancer?
  • Genetic testing