Lynch Syndrome International

 

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Photo Courtesy of Bilal Kamoon

{slider=What is Lynch syndrome?}

Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC) predisposes individuals to an approximate 80% chance of contracting colorectal cancer during one's lifetime as well as an up to 60% chance of contracting endometrial cancer.  Diagnosed individuals possess a higher than average risk of contracting various cancers of the gastrointestinal organs, cancers of the abdominal area, the ovaries, the esophaegus, the bladder, the ureter, the kidneys, the liver, the gallbladder duct, the pancreas, the prostate, the skin and the brain.

Because Lynch syndrome is hereditary, a 50% chance exists that a person will pass it down to one's children.  Lynch syndrome does not skip generations.

Lynch syndrome is the result of an inherited genetic defect mostly involving the MLH1, MSH2, MSH6 and PMS2 genes. Other less common mutated genes involved with Lynch syndrome exist, including the newly discovered MYH gene, associated with Muir Torre and sebaceous lesions. However the most common are the MLH1 and the MSH2.

 

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{slider=What is gene mutation?}

Gene mutations are basically a permanent change in the DNA.  DNA is active and always replicating itself.  If it makes a mistake, then a mutation occurs.

Gene mutations can be inherited or can develop in the sperm or in the egg (called de novo.)  These mutated genes can pass down through the generations. The particular genes of Lynch syndrome are called "mismatch repair genes."  They repair problems (mismatches) that occur during duplication of the genetic code when other genes are made.  If there is a defect in these genes, mismatches won't be repaired properly and cancer cells may develop.

Some gene mutations are a result of environmental factors (such as sun radiation, poor water, ingested foods with DNA altering qualities) and acquired during one's lifetime.  These mutations are not hereditary, however the interplay between the environment and the predisposition to cancers can exacerbate the development of Lynch cancers.

 

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{slider=How common is Lynch syndrome?}

In the general population, the prevalence of Lynch syndrome is predicted between 1-in-500 and 1-in-1,000.  To put this into perspective, It is projected there are approximately 600,000 mutation carriers within the U.S., however it is also projected only 5% of those individuals have been diagnosed, to date.

What we do know is for each individual diagnosed, there are between twenty and over one hundred other related persons who may also be affected and who benefits from that one diagnosis.  A failure to diagnose Lynch syndrome is a failure to diagnose an entire family.

 

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{slider=How is Lynch syndrome diagnosed?}

Lynch syndrome can only be accurately diagnosed through genetic testing.  There are many steps which lead up to this process including the documentation of a family history, shared with your medical provider and/or genetics counselor who will determine whether or not it appears you may be at high risk for Lynch syndrome.

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{slider=What is the difference between Lynch I and Lynch II?}

Lynch I solely refers to families in which colon cancer is the sole contracted cancer.  Lynch II families sustain a variety of cancers, such as endometrial, pelvic-renal, ovarian, etc., in addition to colon cancer.

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{slider=If I get diagnosed, is there a treatment for the cancers?}

Not all persons diagnosed with Lynch syndrome get cancer.   As well, many others develop polyps which are removed by colonoscopy or other intervention before they become cancerous. Besides protecting our children and generations to come, the benefit of diagnosis is the ability to obtain annual testing for cancer, called surveillance testing, which may be lifesaving. So, to answer the question, there is not only treatment through resection (removal of cancers and affected organs) chemotherapy and radiation, but there is also a system of annual testing, which if utilized correctly, growths are removed prior to becoming cancerous!

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{slider=Why does testing need to be completed annually?}

Most cancers take years for the tumors to grow. Lynch syndrome cancers are far more aggressive than other cancers and grow and metastasize very rapidly, often becoming cancerous and dangerous in as little as two years.  Early detection is essential for survival.

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{slider=Is there a cure?}

No.  Researchers have been working very hard to find one.  At Case Western University, Dr. Sanford Markowitz has a vision of finding a way to put the breaks on the mutated gene to counter the mutated gene's attempts to put on the gas!  There are dedicated researchers all over the world trying to figure out what can be done to control the mutation. In the meantime, the closest thing to a cure is genetic testing to determine the existence of the mutated gene and the level of risk.  With that knowledge, implementing annual surveillance testing provides a rate of insurance for early detection of cancer, at a time when it is most treatable and before it becomes a threat to survival.

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{slider=My mother has colon cancer and we think her mother had it, but aren't sure.....}

.......Is there a way we can find out if she  is at  high risk for Lynch syndrome, before proceeding directly toward genetic testing?

Yes. Your mother's tumor can be pathologically tested for certain qualities of Lynch syndrome.  Ask her doctor to refer it for MSI or IHC testing.  Many professional organizations and associations are calling for this testing of the tumor to become a standard of care any time colon cancer or endometrial cancer has been diagnosed.  If the family history indicates there may be a high risk of contracting cancer heritability, always ask for the tumor to be tested through MSI.  The testing is not all that expensive and it may be well worth the investment, if your family history indicates there may be a high risk for Lynch syndrome, for everyone to chip in together and pay for it if insurance doesn't cover the cost.

Remember, the MSI is not a conclusive test.  It is only a presumptive test that would need to be confirmed with genetic testing but it is a good, inexpensive start.

 

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{slider=How many cases of colon cancer in my family should cause concern?}

That depends upon the specifics of your family history.  But, if you have one person in your family with early onset colorectal cancer or with endometrial cancer, it is more than enough to prompt a visit to your physician to discuss Lynch syndrome!

 

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{slider=How serious is the risk of endometrial cancer?}

Endometrial cancer is the most common of women's cancers.  Annually, approximately 40,000 new cases are diagnosed and there are approximately 6,500 deaths.  Every woman has an approximate 2% risk of endometrial cancer however the woman with Lynch syndrome has an almost up to 65% risk of contracting it.  Those are pretty serious numbers. Today, we have put so much focus on "thinking pink" we have forgotten about all the other colors in the cancer rainbow--the dark blues, the teals and the peaches.  It is time to bring notice to the cancers that play dirty and "hit below the belt."

 

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{slider=How serious is the risk of colon cancer?}

Colorectal cancer is the second largest cause of cancer deaths in the U.S. Approximately 150,000 people will be diagnosed with it during 2010 and 60,000 will die.  However the survival rate for those with colon cancer found early is more than 90%.  Individuals with Lynch syndrome have an almost 80% lifetime risk of getting colon cancer.  Therefore, that early detection is important for survival and in order to get that, it is very important to be diagnosed through genetic testing.

 

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{slider=What about the skin cancers?}

Muir Torre syndrome is a variant of Lynch syndrome. It is a genetic syndrome characterized by a combination of sebaceous tumors (tumors of the oil glands in the skin) and one or more internal Lynch malignancies, most often colon cancer.  In the past year, there has been a call to action that all sebaceous tumors be tested through MRI (pathology testing) for Lynch syndrome.

 

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{slider=What is a "biallelic mutation" and how is it different?}

Known as "Turcot syndrome," "Lynch syndrome III and MMR-D syndrome, a biallelic mutation predisposes individuals to an increased risk of developing brain tumors, leukemia, lymphoma, small bowel cancer and colorectal cancer.  It is rare and fewer than seventy-five families in the United States are known to have it.  About 16% are first diagnosed with colorectal cancer and the other introductory cancers are brain cancer, leukemia or lymphoma, prior to development in the gastrointestinal tract.  Commonly recognized feature are numerous colon polyps, which often lead to a mistaken diagnosis of FAP. The average age for colorectal diagnosis is sixteen, however cancers have been diagnosed from infancy through middle adulthood.  A physical feature appearing to be common with this are dark spots on the skin called cafe au lait (CAL) spots.  It has been suggested that any child presenting with an early onset malignancy and cafe au lait spots should be tested for mismatch repair gene presentations. It is believed to occur when both parents have a mutated Lynch syndrome gene.

 

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