Appointments & care

At Mayo Clinic, we take the time to listen, to find answers and to provide you the best care.

Mayo Clinic in Minnesota has been recognized as the best Gastroenterology & GI Surgery hospital in the nation for 2014-2015 by U.S. News & World Report.

Lynch syndrome is an inherited condition that increases your risk of colon cancer and other cancers. Lynch syndrome has historically been known as hereditary nonpolyposis colorectal cancer (HNPCC).

A number of inherited syndromes can increase your risk of colon cancer, but Lynch syndrome is the most common. Doctors estimate that about 3 out of every 100 colon cancers are caused by Lynch syndrome.

Families that have Lynch syndrome usually have more cases of colon cancer than would typically be expected. Lynch syndrome also causes colon cancer to occur at an earlier age than it might in the general population.

Source: http://www.mayoclinic.com

People with Lynch syndrome may experience:

• Colon cancer that occurs at a younger age, especially before age 50
• A family history of colon cancer that occurs at a young age
• A family history of cancer that affects the uterus (endometrial cancer)
• A family history of other related cancers, including ovarian cancer, kidney cancer, stomach cancer, small intestine cancer, liver cancer, sweat gland cancer (sebaceous carcinoma) and other cancers

When to see a doctor

If you have concerns about your family history of colon or endometrial cancer, bring it up with your doctor. Discuss getting a genetic evaluation of your family history and your cancer risk.

If a family member has been diagnosed with Lynch syndrome, tell your doctor. Ask to be referred to a genetic counselor. Genetic counselors are trained in genetics and counseling. They can help you understand Lynch syndrome, what causes it and what type of care is recommended for people who have Lynch syndrome. A genetic counselor can also help you sort through all the information and help you understand whether genetic testing is appropriate for you.

Source: http://www.mayoclinic.com

Lynch syndrome runs in families in an autosomal dominant inheritance pattern. This means that if one parent carries a gene mutation for Lynch syndrome, there's a 50 percent chance that mutation will be passed on to each child. The risk of Lynch syndrome is the same whether the gene mutation carrier is the mother or father or the child is a son or daughter.

How gene mutations cause cancer

The genes inherited in Lynch syndrome are normally responsible for correcting mistakes in the genetic code (mismatch repair genes).

Your genes contain DNA, which carries instructions for every chemical process in your body. As your cells grow and divide, they make copies of their DNA and it's not uncommon for some minor mistakes to occur.

Normal cells have mechanisms to recognize mistakes and repair them. But people who inherit one of the abnormal genes associated with Lynch syndrome lack the ability to repair these minor mistakes. An accumulation of these mistakes leads to increasing genetic damage within cells and eventually can lead to the cells becoming cancerous.

Source: http://www.mayoclinic.com

Appointments & care

At Mayo Clinic, we take the time to listen, to find answers and to provide you the best care.

If it's suspected that you have Lynch syndrome, your doctor may ask you questions about your family history of colon cancer and other cancers. This may lead to other tests and procedures to diagnose Lynch syndrome.

Family history

A family history of colon cancer and other cancers, particularly when they occur at a younger age, may alert your doctor to the possibility that you or members of your family may have Lynch syndrome.

Your doctor may refer you for further Lynch syndrome evaluation if you have:

• Multiple relatives with any Lynch-associated tumors, including colorectal cancer. Examples of other Lynch-associated tumors include those affecting the endometrium, ovaries, stomach, small intestine, kidney, brain or liver.
• Family members diagnosed with cancer at ages that are younger than the average for their type of cancer.
• More than one generation of family affected by a type of cancer.

Tumor testing

If you or someone in your family has been diagnosed with cancer, special testing may reveal whether the tumor has specific characteristics of Lynch syndrome cancers. Samples of cells from a colon cancer and sometimes from other tumors can be used for tumor testing.

If you or someone in your family has been diagnosed with cancer in the last several years, the hospital that provided care may be able to supply a tissue sample. These tissue samples are often stored for many years.

Tumor testing can reveal whether your cancer was caused by the genes related to Lynch syndrome. Tumor tests include:

• Immunohistochemistry (IHC) testing. IHC testing uses special dyes to stain tissue samples. The presence or absence of staining indicates whether certain proteins are present in the tissue. Missing proteins may tell doctors which mutated gene caused the cancer.
• Microsatellite instability (MSI) testing. Microsatellites are sequences of cellular DNA. In people with Lynch syndrome, there may be errors or instability in these sequences in the tumor.

Positive IHC or MSI test results indicate that you have malfunctions in the genes that are connected to Lynch syndrome. But results can't tell you whether you have Lynch syndrome because some people develop these gene mutations only in their cancer cells.

People with Lynch syndrome have these gene mutations in all of their cells. Genetic testing can determine whether you have these mutations.

Increasingly, IHC or MSI testing is being offered to anyone diagnosed with colon cancer to look for signs that may indicate Lynch syndrome. Doctors hope this will help identify families with Lynch syndrome that don't meet the usual criteria for genetic testing.

Genetic testing

Genetic testing looks for changes in your genes that indicate that you have Lynch syndrome. You may be asked to give a sample of your blood for genetic testing. Using special laboratory analysis, doctors look at the specific genes that can have mutations that cause Lynch syndrome.

Results of genetic testing may show:

• A positive genetic test. A positive result, meaning that a gene mutation was discovered, doesn't mean that you're certain to get cancer. But it does mean your lifetime risk of developing colon cancer is increased.

  How much your risk is increased depends on which gene is mutated in your family and whether you undergo cancer screening to reduce your risk of cancer. Your genetic counselor can explain your individual risk to you based on your results.

• A negative genetic test. A negative result, meaning a gene mutation wasn't found, is more complicated. If other members of your family have Lynch syndrome with a known genetic mutation, but you didn't have the mutation, your risk of cancer is the same as the general population.

  If you're the first in your family to be tested for Lynch syndrome, a negative result may be misleading, since not everyone with Lynch syndrome has a genetic mutation that can be detected with current tests. You could still have a high risk of colon cancer — especially if you have a strong family history of colon cancer or your tumor testing revealed a high likelihood of Lynch syndrome.

• A gene variation of unknown significance. Genetic tests don't always give you a yes or no answer about your cancer risk. Sometimes your genetic testing reveals a gene variation with an unknown significance. Your genetic counselor can explain the implications of this result to you.

A positive genetic test. A positive result, meaning that a gene mutation was discovered, doesn't mean that you're certain to get cancer. But it does mean your lifetime risk of developing colon cancer is increased.

How much your risk is increased depends on which gene is mutated in your family and whether you undergo cancer screening to reduce your risk of cancer. Your genetic counselor can explain your individual risk to you based on your results.

A negative genetic test. A negative result, meaning a gene mutation wasn't found, is more complicated. If other members of your family have Lynch syndrome with a known genetic mutation, but you didn't have the mutation, your risk of cancer is the same as the general population.

If you're the first in your family to be tested for Lynch syndrome, a negative result may be misleading, since not everyone with Lynch syndrome has a genetic mutation that can be detected with current tests. You could still have a high risk of colon cancer — especially if you have a strong family history of colon cancer or your tumor testing revealed a high likelihood of Lynch syndrome.

Sometimes genetic testing for Lynch syndrome is done as part of a test for multiple cancer-related genetic mutations. Your genetic counselor can discuss the benefits and risks of genetic testing with you. He or she can explain what genetic testing can tell you and what it can't.

Source: http://www.mayoclinic.com

Beyond complications for your health, a genetic disorder such as Lynch syndrome may be cause for other concerns. A genetic counselor is trained to help you navigate the areas of your life that may be affected by your diagnosis, such as:

• Your privacy. The results of your genetic test will be listed in your medical record, which may be accessed by insurance companies and employers. You may worry that being diagnosed with Lynch syndrome will make it difficult to change jobs or health insurance providers in the future. Federal laws protect Americans from discrimination. A genetic counselor can explain legal protections.
• Your children. If you have Lynch syndrome, your children have a risk of inheriting your genetic mutations. If one parent carries a genetic mutation for Lynch syndrome, each child has a 50 percent chance of inheriting that mutation.
• Your extended family. A Lynch syndrome diagnosis has implications for your entire family. You may worry about the best way to tell family members that you're having genetic testing. A genetic counselor can guide you through this process.

Source: http://www.mayoclinic.com

Frequent cancer screening, preventive surgery and aspirin are options for reducing the risk of cancer in people with Lynch syndrome.

Taking care of yourself through diet, exercise and other lifestyle changes can help improve your overall health.

Take control of your health by trying to:

• Eat a healthy diet full of fruits and vegetables. Choose a variety of fruits and vegetables for your diet. Also, select whole-grain products when possible.
• Exercise regularly. Aim for at least 30 minutes of exercise most days of the week. If you haven't been active, talk to your doctor before you begin an exercise program. Try gentle exercises like walking or biking to get started.
• Maintain a healthy weight. A healthy diet and regular exercise can help you maintain a healthy weight. If you need to lose weight, talk with your doctor about your options. Eating fewer calories and increasing the amount of exercise you do can help you lose weight. Aim to lose 1 or 2 pounds a week.

• Stop smoking. Smoking increases your risk of several types of cancer and other health conditions. Some evidence indicates smoking may increase the risk of colon cancer in people with Lynch syndrome.

  If you smoke, stop. Your doctor can recommend strategies to help you quit. You have many options, such as nicotine replacement products, medications and support groups. If you don't smoke, don't start.

Stop smoking. Smoking increases your risk of several types of cancer and other health conditions. Some evidence indicates smoking may increase the risk of colon cancer in people with Lynch syndrome.

If you smoke, stop. Your doctor can recommend strategies to help you quit. You have many options, such as nicotine replacement products, medications and support groups. If you don't smoke, don't start.

Source: http://www.mayoclinic.com

Knowing that you or your family members have an increased risk of cancer can be stressful. Helpful ways to cope might include:

• Find out all you can about Lynch syndrome. Write down your questions about Lynch syndrome and ask them at your next appointment with your doctor or genetic counselor. Ask your health care team for further sources of information. Learning about Lynch syndrome can help you feel more confident when making decisions about your health.
• Take care of yourself. Knowing that you have an increased risk of cancer can make you feel as if you can't control your health. But control what you can. For instance, choose a healthy diet, exercise regularly and get enough sleep so that you wake feeling rested. Go to all of your scheduled medical appointments, including your cancer-screening exams.
• Connect with others. Find friends and family with whom you can discuss your fears. Talking with others can help you cope. Find other trusted people you can talk with, such as clergy members. Ask your doctor for a referral to a therapist who can help you understand your feelings.

Source: http://www.mayoclinic.com