Lynch Syndrome

February 2, 2017

Lynch syndrome (LS) is a condition that can run in families. It is also known as hereditary non-polyposis colorectal cancer (HNPCC). LS doesn’t cause any symptoms itself. But people with LS have an increased risk of developing bowel cancer, cancer of the womb and some other cancers. If the family has a history of developing these cancers at a young age (under 50), it is possible that people have the altered gene that causes LS.

It is estimated that around 1 in 440 Americans possess a gene mutation associated with Lynch syndrome. The condition is most commonly associated with greater risk of colorectal cancer, accounting for around 3-5% of all cases. Women with Lynch syndrome, however, are also at 40-60% greater risk of endometrial cancer – a cancer that begins in the lining of the uterus, called the endometrium.

Some people with Lynch syndrome may also develop sebaceous adenomas, which are noncancerous tumors of an oil-producing gland in the skin.

Lynch syndrome is caused by a change in a gene that normally functions to protect a person from getting cancer. If you have a parent or sibling with Lynch syndrome, you are potentially at risk of developing Lynch syndrome. If you have been diagnosed with Lynch syndrome, your children are at risk. When a parent carries a change known as a mutation, in one of the Lynch syndrome genes, they have one working and one non-working copy of the gene. Each child will have a 50% chance of inheriting the gene mutation.

Not everyone with Lynch syndrome will develop bowel cancer. A person who inherits a Lynch syndrome mutation has around 30-50% chance of developing cancer (risks vary depending upon which gene is affected) unless preventative measures are taken. Developing bowel cancer at a young age is not uncommon.


Lynch Syndrome is caused by an abnormality in one of four mismatch repair genes (MLH1, MSH2, MSH6, and PMS2). These are the genes responsible for correcting mistakes that occur in genes when body cells divide.   More recently an error in a gene called EPCAM has been identified and this also stops the MSH2 gene working properly meaning it can’t fix up those “spelling” mistakes.

Nearly every cell in our bodies contains two copies of each gene and genes are the “instruction manuals” for building and running the body. DNA is the genetic material within each cell that contains instructions for every chemical process in the cells of the body. As cells grow and divide they make copies of their DNA and it is common for minor mistakes to occur.   Normally the mismatch repair genes recognize these mistakes and repair them, similar to the “spell check” function on your computer. However, people who inherit a fault in one of the four mismatch repair genes lack the ability to repair these minor mistakes. An accumulation of these mistakes may eventually lead to the development of a cancer.    


Men and women can inherit a gene mutation associated with Lynch syndrome from either their mother or father. People with one of these mutations can also pass it on to their children. If one parent has the mutation in 1 of the 2 copies of a Lynch syndrome gene, a child has a 50% chance of inheriting the gene mutation. This also means there is a 50% chance that a child will not inherit the gene mutation.

Healthcare professionals use certain criteria to determine if a Lynch syndrome gene mutation may be present in a family. These are referred to as the Amsterdam criteria.

  • At least 3 family members have colorectal cancer or another cancer related to Lynch syndrome. At least 1 of these family members is a first-degree relative (parent, sibling or child) of the other 2 family members.
  • At least 1 family member was diagnosed with cancer before age 50.
  • Cancer occurs in at least 2 generations in a row.
  • FAP has been ruled out.


People with Lynch syndrome may have –

  • Colon cancer that occurs at a young age, especially before age 45
  • A family history of colon cancer that occurs at a young age
  • A family history of endometrial cancer
  • A family history of other related cancers, including ovarian cancer, kidney cancer, stomach cancer, small bowel cancer, liver cancer or other cancers

Those with Lynch syndrome have a 70 percent chance of developing colon cancer by age 70. Colon cancer patients with Lynch syndrome have an estimated 40 percent risk of developing a second primary colon cancer within seven years of being diagnosed after the first tumor. Women with Lynch syndrome have a 40 percent to 60 percent estimated lifetime risk of developing endometrial cancer.

Lynch syndrome may also increase a person’s risk for cancers of the stomach, ovary, urinary tract, hepatobiliary tract, brain, small intestine, skin and pancreas.


Surgery is recommended to remove the colon (subtotal colectomy) if colon cancer is detected in someone with a known diagnosis of Lynch syndrome due to the high risk for second primary colon cancers. Surgery to remove the uterus and ovaries before cancer develops (prophylactic) is a consideration for women who have Lynch syndrome and have completed childbearing. Individuals with Lynch syndrome should be monitored every one or two years with examinations of the colon (colonoscopy) beginning at age 20-25 or 2 to 5 years before the youngest age that a family member was diagnosed, whichever is earlier. Prophylactic removal of the colon is not usually recommended because colonoscopy is usually effective in detecting colon cancer at an early stage or at preventing colon cancer entirely.

Genetic counseling is recommended for affected individuals and their family members. Other treatment is symptomatic and supportive.

Alternative Treatment

Calcium & Vitamin D – There is evidence that higher calcium and vitamin D intake lowers the risk of developing colon cancer.

Folic Acid – In observational studies, low folate has been linked to increased risk of colon cancer. However, some data suggest that high intake of folate may have a paradoxical effect, raising the risk of developing colorectal cancer in some individuals.

Selenium – In several studies, selenium status was lower in those with adenomas and colon cancer versus controls. One study of selenium-deficient patients with a history of adenomas showed that repletion of selenium corrected both selenium status and activity of glutathione peroxidase in the colonic mucosa.

Curcumin, the collective term for the 3 curcuminoids that give Turmeric (Curcuma longa) its distinct yellow color, may be the most well-characterized chemopreventative agent from any spice. Spices are collectively composed of a myriad of chemopreventative phytochemicals, including phenolics, terpenoids, and flavonoids

Omega-3 fatty acids – Omega 3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have potent anti-inflammatory effects. There is also evidence for direct protective effects regarding proliferation, apoptosis, angiogenesis, and metastasis in colon cancer cells.

Garlic (Allium sativum) – The anticarcinogenic effects of garlic are thought to be derived primarily from organosulfur compounds, including the odiferous diallyl sulfide that gives garlic its distinct smell.106 Garlic and its constituents have been well proven to lessen CRC carcinogenesis, reduce proliferation, block angiogenesis, induce differentiation and apoptosis, inhibit cyclooxygenase-2 and squelch free radical.

Probiotics – The interplay between dietary components and the microbiota of the colon is thought to have a integral role in carcinogenic processes of the colonic epithelium, as well as overall health and disease. The short-chain fatty acid butyrate is a product of microbiota metabolism of fiber from the diet, and butyrate is involved in colonic homeostasis of colonic crypts. Many other compounds formed from microflora may influence the inflammatory environment of the colon, systemic immune function, and the presence of bioactive compounds locally that may promote or inhibit carcinogenic processes.

Green tea components such as polyphenols (eg, epigallocatechin-3-gallate, EGCG) can affect colorectal carcinogenic processes.


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