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Lynch syndrome: causes, symptoms and treatments



Definition

Lynch syndrome is an inheritance that increases the risk of colon cancer and other cancers. Lynch syndrome has been known in the past as hereditary colorectal carcinoma without polyposis (HNPCC).

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

Families who have Lynch syndrome usually have more cases of colon cancer than would normally be expected. The Lynch syndrome also causes an earlier occurrence of colon cancer than in the general population.

Symptoms

In people with Lynch syndrome, the following can occur:

  • Colon carcinoma that occurs before the age of 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 bowel cancer, liver cancer, sweat gland cancer (sebaceous gland) and other cancers

If you see a doctor

If you have concerns about your family history of colon cancer or uterine cancer, talk to doctor. Discuss a genetic assessment 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 with Lynch syndrome. A genetic counselor can also help you sort out all the information and understand if genetic testing is right for you.

Causes

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

How gene mutations cause cancer

The genes inherited from Lynch syndrome are usually responsible for the correction of errors in the genetic code (mismatch repair genes).

Your genes contain DNA that contains 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 minor bugs to occur.

Normal cells have mechanisms to detect and repair errors. But people who inherit one of the abnormal genes associated with Lynch syndrome can not repair these minor flaws. An accumulation of these defects leads to increased genetic damage in the cells and can ultimately cause the cells to become cancerous.

Complications

Aside from complications to your health, a genetic disorder such as Lynch syndrome can cause other problems. 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 are listed in your medical record and employers. You may be worried that diagnosing Lynch syndrome may make it difficult to change jobs or health insurers in the future. Federal laws protect Americans from discrimination. A genetic counselor can declare legal protection.
  • Your children. If you have a Lynch syndrome, there is a risk your children will inherit genetic mutations. If a parent carries a genetic mutation for the Lynch syndrome, each child has a 50 percent chance of inheriting that mutation.
  • Your extended family. A diagnosis of Lynch syndrome affects your entire family. You may be worried about best telling your family members that you have genetic testing. A genetic counselor can guide you through this process.

Preparing for Your Date

If your doctor thinks you may have Lynch syndrome, you may be referred to a genetic counselor.

A genetic counselor can give you information You can decide if lab tests are useful for diagnosing Lynch syndrome or another genetic disorder. If you decide to take the test, a genetic counselor can explain what can mean a positive or negative result for you.

What You Can Do

To prepare for a meeting with the genetic counselor:

  • Collect your doctor's records. If you had cancer, bring your medical records to your appointment with the genetic counselor.
  • Ask family members who have cancer for information. If your family members have cancer, ask for information about their diagnosis. Make a note of the cancers, the types of treatment and the age at diagnosis.
  • Consider taking a family member or friend with you. It can sometimes be difficult to remember all the information made during an appointment. Someone who accompanies you can remember something that you missed or forgot.
  • Write questions to ask your genetic counselor.

Questions to Ask

Prepare a list of questions that ask your genetic counselor. Questions could be:

  • Can you explain how the Lynch syndrome occurs?
  • How do gene mutations occur?
  • How are the gene mutations associated with Lynch syndrome traversed by families?
  • If I have a family member Lynch Syndrome, what's the chance I have too?
  • What types of tests are involved in genetic testing?
  • What will the results of genetic testing show me?
  • How long can I expect? for my results?
  • If my genetic test is positive, how big is the chance that I will get cancer?
  • What types of cancer screenings can detect Lynch-related cancers at an early stage?
  • If my genetic test is negative, does that mean that I can not get cancer?
  • How many gene mutations are overlooked in current genetic testing?
  • What do my genetic test results mean for my family?
  • How much does genetic testing cost?
  • Does my insurance pay for genetic testing?
  • Which laws protect me? of genetic discrimination if my genetic tests are positive?
  • Is it okay to opt for genetic testing?
  • If I do not want to choose genetic testing, what does that mean for my future health?
  • Are there brochures or other printed material I can take with me? Which websites do you recommend?

In addition to the questions you have asked your adviser, you may ask further questions when you are appointed.

What You Can Expect From a Genetic Advisor

The genetic counselor will likely ask you a series of questions about your health history and the health history of your family members. Your genetic counselor might ask:

  • Have you been diagnosed with cancer?
  • Have family members been diagnosed with cancer?
  • At what age was each member of the family diagnosed with cancer?
  • Do you have family members? Have you ever had genetic tests?

Tests and Diagnosis

If you suspect you have Lynch Syndrome, your doctor may ask you questions about the family history of colon cancer and other cancers. This can lead to other tests and procedures for diagnosing Lynch Syndrome.

Family History

A family history of colorectal cancer and other cancers, especially if they occur at a young age, may alert your doctor to the possibility that you or your family members may have a Lynch syndrome.

Your doctor may refer you to further evaluation of Lynch syndrome if you:

  • have multiple relatives with a lynch-associated tumor, including colon cancer. Examples of other lynch-associated tumors include those involving the endometrium, ovaries, stomach, small intestine, kidneys, brain, or liver.
  • Family members who have been diagnosed with cancer at an age younger than the average of their cancer. 19659075] More than one family generation affected by a cancer.

Tumor Test

If you or any of your family members have been diagnosed with cancer, specific tests may show whether the tumor has specific features of Lynch syndrome. Samples from cells of a colon cancer, and sometimes other tumors, can be used for tumor testing.

If you or a family member have been diagnosed with cancer in recent years, the hospital that performed the treatment may be provided with a tissue sample. These tissue samples are often stored for many years.

Tumor tests can show if your cancer was caused by the genes associated with Lynch syndrome. Tumor tests include:

  • Immunohistochemistry (IHC) testing. In the IHC test tissue samples are stained with special dyes. The presence or absence of staining indicates whether certain proteins are present in the tissue. Missing proteins could tell the doctors which mutant gene caused the cancer.
  • Microsatellite Instability Test (MSI). Microsatellites are sequences of cellular DNA. In humans with Lynch syndrome, these sequences may be defective or unstable in the tumor.

Positive IHC or MSI test results indicate malfunction of the genes associated with Lynch syndrome. However, the results can not tell if you have Lynch syndrome because some people only develop these gene mutations in their cancer cells.

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

Increasingly, IHC or MSI tests are being offered to every colorectal cancer patient for signs of Lynch syndrome. Doctors hope that this will identify families with Lynch syndrome who do not meet the usual criteria for genetic testing.

Genetic Testing

Genetic testing is looking for changes in your genes that indicate a Lynch syndrome. You may be asked to give a blood test for genetic testing. In a special laboratory analysis, doctors are studying the genes that may have mutations that cause Lynch syndrome.

Results of genetic testing may show:

  • A positive genetic test. A positive result, ie a gene mutation has been discovered, does not mean that you are sure to get cancer. However, it does mean that your lifetime risk of colon cancer is elevated.

    How much your risk is increased depends on which gene in your family has mutated and whether you are undergoing cancer screening to lower your risk of cancer. Your genetic counselor can use your results to explain your individual risk.

  • A negative genetic test. A negative result, ie a gene mutation was not found, is more complicated. If other family members have a known genetic mutation in a Lynch syndrome but the mutation was not, the risk of cancer is the same as that of the general population.

    If you are the first in your family to have Lynch syndrome tested, a negative result can be misleading because not everyone with Lynch syndrome has a genetic mutation that can be detected with current tests. You may still be at high risk for colorectal cancer – especially if you have a strong family history of colon cancer or if your tumor test showed a high likelihood of Lynch syndrome.

  • A gene variation of unknown significance. Genetic tests do not always give you a yes or no to your cancer risk. Sometimes your genetic tests show a gene variation of unknown importance. Your genetic counselor can explain the implications of this result.

Sometimes genetic tests for Lynch syndrome are performed as part of a test for multiple cancer-related genetic mutations. Your genetic counselor can discuss with you the benefits and risks of genetic testing. He or she can explain what genetic tests can and can not tell you.

Treatments and Medicines

Colon cancer associated with Lynch syndrome is treated similarly to other types of colon cancer. However, lynch syndrome surgery for colon cancer is more likely to remove more bowel, as people with Lynch syndrome are at an increased risk of developing additional colorectal cancer in the future.

Your treatment options depend on the stage and location of your cancer as well as your own health, age and personal preferences. The treatment of colorectal cancer may include surgery, chemotherapy and radiotherapy.

Cancer Screening in Patients with Lynch Syndrome

If you have a Lynch syndrome but no associated cancer has been diagnosed – sometimes called a "precursor" – your doctor may develop a cancer screening plan for you.

Follow the plan recommended by your doctor. Screening for cancer can help your doctor find tumors at their earliest stages – and more likely to get them healed.

It has not been found out which cancer diagnostic tests are best for people with Lynch syndrome. As a result, medical groups vary which tests they recommend. Which tests are best for you may depend on your family history and what gene is causing Lynch syndrome.

As part of your cancer care plan, your doctor may recommend:

  • Colorectal cancer screening. In colonoscopy, your doctor can look at your entire colon and look for areas of abnormal growth that may indicate cancer. Colorectal cancer screening reduces the risk of death from colon cancer by removing pre-cancerous growths (polyps). People with Lynch syndrome usually start colonoscopy every one to two years.

    People with Lynch syndrome tend to develop colonic polyps that are more difficult to detect. For this reason, newer colonoscopy procedures may be recommended. High-resolution colonoscopy produces more detailed images and narrow-band colonoscopy uses special light to produce clearer images of the colon. Chromoendoscopy uses dyes to stain the colon tissue, increasing the likelihood of detecting the more common polyp with polyps with Lynch syndrome.

  • Endometriumkrebsscreening. Women with Lynch syndrome may annually experience endometrial biopsy or ultrasound for the early detection of cancer from the age of 30 years.

  • ovarian cancer screening. To assess the ovaries, an ultrasound can be used, which can be recommended from the age of 30 years. By comparing the annual ultrasound scans, your doctor may detect changes in your ovaries that indicate cancer. Your doctor may also recommend annual blood tests.

  • Cancer screening of the urinary system. Your doctor may recommend a periodic screening for urinary tract cancer. Analysis of a urine sample can reveal blood or cancer cells.

  • Gastrointestinal Cancer Screening. Your doctor may recommend endoscopy screening for stomach cancer and small bowel cancer. Through an endoscopy procedure, your doctor can see your stomach and other parts of your digestive system.

While research has proven the effectiveness of colorectal cancer screening to reduce the mortality risk of the disease, similar research has not proven the effectiveness of screening for the other cancers. Nevertheless, experts recommend screening for these other cancers, although there is no evidence.

Your doctor may recommend other cancer screening tests if your family has had other cancers in the past. Ask your doctor which screening tests are best for you.

Aspirin for cancer prevention

Recent studies indicate that taking a daily aspirin may reduce the risk of various cancers associated with Lynch syndrome. Further studies are needed to confirm this. Discuss the potential benefits and risks of aspirin therapy to see if this could be an option for you.

Surgery for the prevention of cancers caused by the Lynch syndrome

In certain situations, patients with a Lynch syndrome may consider surgery to reduce the risk of cancer. Discuss the benefits and risks of preventive surgery with your doctor.

Surgical options for the prevention of cancer may include:

  • A colon removal surgery (colectomy). Surgery to remove most or the entire bowel reduces or eliminates the chance that you will get colon cancer. This procedure can be performed in a way that allows you to expel waste normally, without having to carry a bag outside of your body to collect waste.

    There is little evidence that removing your colon has an advantage over frequent cancer screening. to help you live longer. However, some people prefer peace of mind or avoid frequent colonoscopy examinations.

  • Through the surgery for removal of the ovaries and the uterus (oophorectomy and hysterectomy). Through the preventive surgery of uterine removal, you can no longer develop endometrial carcinoma in the future. Removal of the ovaries can reduce the risk of ovarian cancer.

    Unlike colon cancer, screening for ovarian cancer and uterine cancer can not detect cancer risk. Because of this, doctors usually recommend preventive surgery for women who have completed carrying children.

Coping and Support

Knowing that you or your family members are at an increased risk of cancer can be exhausting. Helpful ways to deal with this could be:

  • Find out about Lynch syndrome. Write down your questions about Lynch syndrome and ask your doctor or genetic counselor about your next appointment. Ask your health care team for more information. Learning about Lynch Syndrome can make you feel safer when making decisions about your health.
  • Take care of yourself. If you know that you have an increased risk of cancer, you may feel that you can not control your health. But control what you can. For example, choose a healthy diet, exercise regularly, and sleep enough to feel well rested. Go to all your scheduled medical appointments, including your cancer screening tests.
  • Connect with others. Find friends and relatives to discuss your fears. Talking to others can help you cope with it. Find other trusted people to talk to, such as: B. Clergymen. Ask your doctor for a referral to a therapist who can help you understand your feelings.

Prevention

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

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

Take control of your health by trying to

  • eat a healthy diet of fruits and vegetables. Choose a variety of fruits and vegetables for your diet. If possible, also choose whole-grain products.

  • Regular exercise. Most days of the week, you should move for at least 30 minutes. If you were not active, talk to your doctor before starting an exercise program. Try light exercises such as walking or cycling.

  • Keep a healthy weight. A healthy diet and regular exercise can help you maintain a healthy weight. If you need to lose weight, talk to your doctor about your options. Eating fewer calories and increasing physical stress can help you lose weight. Lose 1 or 2 pounds per week.

  • Stop smoking. Smoking increases your risk for various types of cancer and other health conditions. Some evidence suggests that smoking increases the risk of colorectal cancer in patients with Lynch syndrome.

    If you smoke, stop. Your doctor may recommend strategies to help you stop. You have many options, eg. As nicotine replacement products, drugs and support groups. If you do not smoke, do not start.

Updated: 2015-03-13

Release date: 2006-01-23


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