WHAT IS LYNCH SYNDROME?
WHAT EXACTLY IS
LYNCH SYNDROME?
Lynch Syndrome (previously known as hereditary non-polyposis colorectal cancer (HNPCC)) is a common but underdiagnosed inherited genetic cancer syndrome that significantly increases the risk of colorectal, uterine/endometrial, and many other cancers compared to the general population.
It is the most common type of inherited colorectal cancer. Lynch Syndrome is passed down through families. It occurs when a person inherits a mutation in one of the genes responsible for DNA repair. There are 5 of these genes associated with Lynch Syndrome: MLH1, MSH2, MSH6, PMS2, and EPCAM. These genes are called mismatch repair (MMR) genes. These MMR genes are normally responsible for fixing errors, or “mismatches,” when our cells divide, and DNA is copied over to the new cells. A mutation in one of these repair genes causes the gene to not work properly, which allows errors to occur and accumulate.
Accumulation of these errors can lead to uncontrolled cell division and, eventually, cancer. Cancers associated with Lynch Syndrome are more likely to occur at a young age, and those who have Lynch Syndrome are also at an increased risk of developing multiple types of cancer during their lifetime. Although having mutations in these genes predisposes you to cancer, not everyone who has Lynch Syndrome will develop cancer.
WHAT GENES ARE ASSOCIATED WITH LYNCH SYNDROME?
There are currently 5 genes associated with Lynch Syndrome (MLH1, MSH2, MSH6, PMS2, EPCAM). Lynch Syndrome occurs when you inherit a copy of 1 of these 5 genes that is not working properly.
These genes, when working properly, protect you from getting cancer by correcting mistakes when your cells divide and copy your genetic information (your DNA) to the new cells. Think of these genes as being similar to when you are typing something and you make a typo, but spellcheck is able to fix those typos. Because you have one of these genes that is not working properly, these “typos” can accumulate over time and these mistakes may lead to cancer.
HOW COMMON IS LYNCH SYNDROME?
Current estimates are that 1 in 279 people has Lynch Syndrome. An estimated 95% of those who have inherited Lynch Syndrome are not aware they have Lynch Syndrome.
In recent years, other inherited cancer syndromes have received media attention, such as hereditary breast and ovarian cancer syndrome caused by mutations in the BRCA1/2 genes, which are present in 1 in 400 people in the United States. Lynch Syndrome is MORE common, but has LESS awareness.
An estimated 1 in 279 people has Lynch Syndrome.
WHY IS IT IMPORTANT TO KNOW IF YOU HAVE LYNCH SYNDROME?
It could save your life.
If you could do something to detect cancer early when it can be treated, cured, or possibly prevented, wouldn’t you want to know? When you know you have Lynch Syndrome, you can adopt life saving strategies for cancer prevention, early detection and treatment, and risk reducing surgeries. For example, in the case of colorectal cancer, polyps detected during a colonoscopy can be removed before they turn into cancer or at an early stage when the cancer can be cured. Visit this link to learn more.
Your cancer care could be treated differently if caused by Lynch Syndrome. You can adapt life-saving screening strategies to prevent or catch cancer early when it can be treated effectively.
It could save your family member’s life.
Because Lynch Syndrome is inherited, other members of your family may have inherited Lynch Syndrome. Knowing your risk is not only important for saving your life, but the lives of your family members as well.
HOW IS LYNCH SYNDROME INHERITED?
Lynch Syndrome is an inherited genetic condition caused by a mutation in one of 5 genes. Mutations in the genes associated with Lynch Syndrome can be passed from generation to generation in families. Lynch Syndrome follows an autosomal dominant inheritance pattern. Autosomal dominant means a person only needs to inherit one copy of the abnormal gene to develop the condition. It does not skip generations, and it affects both men and women. A parent with Lynch Syndrome has a 50/50 chance of passing the condition to each of his or her children, regardless of biological sex.
WHAT ARE THE CANCER RISKS ASSOCIATED WITH LYNCH SYNDROME?
General lifetime cancer risks for people with Lynch Syndrome according to the American Society of Clinical Oncologists (ASCO):
Lynch Syndrome has been linked to higher risks of other types of cancers as well, including kidney and skin cancers. Cancers can develop at a much younger age than normal, and colon polyps become cancerous more rapidly than in the general population.
WHAT ARE THE CANCER SCREENING OPTIONS FOR THOSE WITH LYNCH SYNDROME?
People with Lynch Syndrome generally begin cancer screenings earlier than the general population. Clinical guidelines have been published by the American Society of Clinical Oncologists, the National Comprehensive Cancer Network, and others to help guide screening and care for people with Lynch Syndrome. It is important to discuss these options with your doctor, as each individual is different:
General screening and risk-reduction guidelines
Colonoscopy every 1 to 2 years, beginning between the ages of 20 to 25 or 5 years younger than the earliest age at diagnosis in the family, whichever is sooner. For some Lynch Syndrome carriers, such as those with MSH6 or PMS2 mutations, screening may begin later.
Upper endoscopy every 3 to 5 years, in addition to testing for Helicobacter pylori infection at a baseline exam with treatment if positive.
Annual total body skin examination.
Consideration of a daily aspirin, which has been linked to a reduced risk of colorectal cancer and possibly other cancers in individuals with Lynch Syndrome.
Screening for other cancers linked with Lynch Syndrome may be recommended depending on a person’s family history, though the effectiveness of such screening remains unproven.
Screening for women
Yearly pelvic examination, pelvic ultrasound, endometrial biopsy, from age 30 to 35. Women who are finished having children may want to consider having preventive surgery to remove the uterus and ovaries, especially since screening for endometrial and ovarian cancer has not yet proven to be effective in women with Lynch Syndrome.
Screening options may change over time as new technologies are developed and more is learned about Lynch Syndrome and its other forms. It is important to talk with your doctor about appropriate screening tests.
Screening for other Lynch Syndrome-related cancer risks should be discussed with your doctor, as each person’s risks are different based on the gene affected. You should consult a physician who is familiar with and knowledgeable about Lynch Syndrome to determine the proper screening for you.
Source: https://www.nccn.org/professionals/physiciangls/pdf/genetics_ceg.pdf_ceg.pdf
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Source:
www.cancer.net/cancer-types/lynch-syndrome
The information provided on this website is not intended as medical advice. It should not be considered as a substitute for consulting with a physician or medical professional familiar with you personal health and medical needs.