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What Is The Genetic Marker For Breast Cancer

How Do I Interpret The Genetic Test Results

Cancer Researchers Discover Dozens of New Genetic Markers

A negative genetic test means that a breast cancer gene mutation was not identified. If other genetic testing has identified a mutation in your family, a negative test means you do not have the specific mutation. Therefore, your risk of cancer is the same as someone in the general population who has a family history of breast cancer.

If a BRCA1 or BRCA2 mutation has not been previously found in your family, a negative result should be interpreted cautiously. There is still a chance that you may be at higher risk for breast cancer because of changes in genes other than those that doctors can test for.

A positive test result means that a mutation known to raise the risk of breast and ovarian cancer was identified.

If I Have A Brca Gene Mutation Will I Get Cancer

A BRCA mutation increases the risk of getting certain types of cancers, Clayback says. However, not all people with BRCA mutations will get cancer.

For example, approximately 12% of women in the general population will develop breast cancer at sometime in their lives. But, for women with a BRCA1 or BRCA2 mutation, the risk of developing breast cancer increases to as much as 72%. Likewise, about 1 to 2% of women in the general population will develop ovarian cancer sometime during their lives, but up to 44% of women who inherit a harmful BRCA1 mutation and about 17% of women who inherit a harmful BRCA2 mutation will develop ovarian cancer by the age of 80.

How Are Brca1 And Brca2 Genetic Mutations Passed Down Through A Family

BRCA1 and BRCA2 genetic mutations can be passed from a mother or father to a son or daughter.

People with a first-degree relative with a BRCA1 or BRCA2 mutation have a 50% chance of having inherited themutation.

Mutations in the BRCA1 and BRCA2 genes have been found in people all over the world. However, some genetic mutations may be more common in certain ancestral groups. For example, three BRCA1 and BRCA2 genetic mutations are particularly common among Ashkenazi Jewish families. Ashkenazi Jewish families typically have origins in Eastern Europe. One in 40 Ashkenazi Jewish individuals carry one of these common BRCA mutations.

Through MSKs RISE Program, our experts help people who have an increased risk of breast cancer shape personalized long-term surveillance plans.

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What Are The Potential Problems With Genetic Testing

Genetic testing is not 100% accurate. If a test is negative, a person still has a chance of getting breast cancer. If the test is positive, there is still a 15% to 20% chance of not getting breast cancer.


Genetic testing is costly, ranging from about $400 to more than $3,000, depending on the type of test. Insurance coverage varies.

The results of genetic tests won’t be available for several weeks. The length of time it takes to get results depends on the tests performed and under what circumstances they are done.

Genetic testing is very controversial. Legislation has been enacted to protect people who may have a documented genetic risk of cancer from employment or insurance problems. The best thing you can do is to become involved with an established genetic registry that can counsel people who have a genetic risk for cancer.

If I Test Positive For A Brca Mutation Can I Be Discriminated Against

Breast cancer classification: histology, molecular markers ...

In 1996, the US Congress passed the Health Insurance Portability and Accountability Act , which included protection against genetic testing information being used in a discriminatory manner towards individuals in a group health plan. In 2008, the U.S. Congress passed another law, theGenetic Information Nondiscrimination Act, or GINA, to protect citizens against health insurance or employment discrimination based on their genetic information. The law says health insurance companies cannot raise premiums or claim a pre-existing condition based only on genetic testing results. Likewise, employers cannot make hiring, firing or salary decisions based on a person’s genetic information.

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Whats An Example Of How Tumor Marker Testing Can Guide Cancer Care

Understanding how tumor markers can affect your treatment choices can be complicated, but asking for examples can help. For instance, early-stage breast cancer has specific tumor markers that can help doctors tailor an individuals treatment. If a person is diagnosed with this disease, the doctor may test for tumor markers known as estrogen receptor and progesterone receptor . If the tests are positive for them, her doctor knows that the patient is more likely to be treated successfully with hormone therapy.

If your doctor suggests tumor marker testing, ask which tumor markers youll be tested for and how often. Also, ask what the doctor hopes to learn from the testing.

How Are Tumor Marker Tests Done

There are 3 ways your doctor can test for tumor markers: a blood test, a urine test, or a biopsy. A member of your health care team will send a sample of your blood or urine into a laboratory for analysis. If a biopsy is done, a doctor will remove a small amount of tissue that will be examined by a pathologist under a microscope. You may need to repeat your tumor marker tests, because your tumor marker levels can change over time.

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What Are The Options If I Test Positive

You have several options to manage your cancer risk.

Surveillance: Surveillance: Begin cancer screenings at an earlier age , including yearly mammography and breast MRI. Clinical breast exams every six months starting at age 18 and practicing breast self awareness.

Surgery: Women typically have their ovaries and fallopian tubes removed, which reduces the risk of both breast and ovarian cancer and fallopian tube cancer. Timing of ovarian and fallopian tube removal is important, and should take into consideration both family planning and the usual age at which ovarian cancer develops in those with BRCA gene mutations. Women may also choose to have their breasts removed.consider prophylactic bilateral mastectomy to reduce their risk of developing breast cancer.

Medication: Three drugs have been shown to decrease the risk of breast cancer: tamoxifen and raloxifene, and exemestane. Both are taken as a daily pill.

Risk avoidance: Certain lifestyle behaviors have been linked to cancer risk, including eating a diet that is high in fruits and vegetablesdiet, limiting alcohol consumption, tobacco cessation, and increasing physical activity.

Talk to your doctor about the options that are best for you.

Should I Be Tested For Brca Mutations

Genetic Counseling / Breast Cancer BRCA Gene

A genetic counselor can help you understand if you’re likely to have an inherited susceptibility to breast and/or ovarian cancer. Those most appropriate for genetic testing have:

  • High numbers of family members with cancer diagnoses throughout several generations, either maternal or paternal
  • Family member diagnosed with cancer before age 50
  • Family members who have been diagnosed with multiple cancers
  • Male breast cancers, or clusterings of other cancers such as colon, prostate, stomach or pancreatic

Women who have none of these family history patterns have a low probability of having a harmful BRCA1 or BRCA2 mutation.

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Implications For Genetic Testing

The results presented above on the morphological and immunohistochemical characteristics of hereditary breast cancer illustrate major differences between genotypes. The most important were those between tumors in BRCA1 carriers and all other categories. These histopathological features, in conjunction with clinical data, can be used to predict BRCA1 status and, to a lesser extent, BRCA2 and non-BRCA1/2 status and this could have implications for the process of mutation screening.

In families with a high incidence of breast and ovarian cancer there is a high probability of finding a BRCA1 or BRCA2 germline mutation. In the absence of other clinical features suggesting the alteration of a specific gene, such as prostate cancer and BRCA2 mutations, histopathological features can be used to indicate which gene should be screened first. Grade 3, estrogen receptor- and progesterone receptor-negative infiltrating ductal carcinomas are more common among BRCA1 patients, specially if they show medullary features. These cases should be also tested for CK5/6 and EGFR expression, since the positive staining of any of these makers further increase the probability of being a BRCA1 mutation carrier. Estrogen receptor- and/or progesterone receptor-positive tumors without evidence of basal differentiation should first be tested for BRCA2 mutations.

What To Do If You’re Worried

Speak to a GP if cancer runs in your family and you’re worried you may get it too. They may refer you to a local genetics service for an NHS genetic test, which will tell you if you have inherited one of the cancer risk genes.

This type of testing is known as predictive genetic testing. It’s “predictive” because a positive result means you have a greatly increased risk of developing cancer. It does not mean you have cancer or are definitely going to develop it.

You may be eligible for this NHS test if the faulty gene has already been identified in one of your relatives, or if there is a strong family history of cancer in your family.

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How It Is Done

The health professional taking a sample of your blood will:

  • Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
  • Clean the needle site with alcohol.
  • Put the needle into the vein. More than one needle stick may be needed.
  • Attach a tube to the needle to fill it with blood.
  • Remove the band from your arm when enough blood is collected.
  • Put a gauze pad or cotton ball over the needle site as the needle is removed.
  • Put pressure on the site and then put on a bandage.

Breast And Gynecologic Cancer Susceptibility Genes Identified Through Candidate Gene Approaches

Predictive molecular markers of breast cancer.

There is a very large literature of genetic epidemiology studies describing associations between various loci and breast cancer risk. Many of these studies suffer from significant design limitations. Perhaps as a consequence, most reported associations do not replicate in follow-up studies. This section is not a comprehensive review of all reported associations. This section describes associations that are believed by the editors to be clinically valid, in that they have been described in several studies or are supported by robust meta-analyses. The clinical utility of these observations remains unclear, however, as the risks associated with these variations usually fall below a threshold that would justify a clinical response.

Fanconi anemia genes

Fanconi anemia is a rare, inherited condition characterized by bone marrow failure, increased risk of malignancy, and physical abnormalities. To date, 16 FA-related genes, including BRCA1 and BRCA2, have been identified . FA is mainly an autosomal recessive condition, except when caused by pathogenic variants in FANCB, which is X-linked recessive. FANCA accounts for 60% to 70% of pathogenic variants, FANCC accounts for approximately 14%, and the remaining genes each account for 3% or fewer.



Currently, the clinical applicability of CHEK variants remains uncertain because of low variant prevalence and lack of guidelines for clinical management.








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How Common Is Hboc

Most breast and ovarian cancers are sporadic, meaning they occur by chance with no known cause. Most women who have breast or ovarian cancer do not have HBOC.

Currently, it is estimated that less than 1% of the general population has a mutation in the BRCA1 or BRCA2 genes, and up to 10% of women and 20% of men diagnosed with breast cancer have a mutation in 1 of these genes. About 10% to 30% of women younger than 60 diagnosed with triple-negative breast cancer, which are cancers that do not have receptors for estrogen, progesterone, and HER2, have a BRCA1 or BRCA2 gene mutation, and others will have mutations in other breast cancer risk genes. Therefore, doctors recommend that women with triple-negative breast cancer receive genetic counseling and genetic testing .

HBOC is most common in families who have had multiple cases of breast cancer and/or ovarian cancer on the same side of the family. In families with 4 or more cases of breast cancer diagnosed before age 60, the chance of HBOC is about 80%. To compare, the chance of finding HBOC when only 1 woman has had breast cancer diagnosed before age 50 is estimated to be 10% or less.

Families with Ashkenazi Jewish ancestry have an increased chance of having HBOC. There are 3 specific gene mutations, known as founder mutations, that are common in these families:

  • 185delAG in BRCA1

  • 5382insC in BRCA1

  • 6174delT in BRCA2

Having Dense Breast Tissue

Breasts are made up of fatty tissue, fibrous tissue, and glandular tissue. Breasts appear denser on a mammogram when they have more glandular and fibrous tissue and less fatty tissue. Women with dense breasts on mammogram have a risk of breast cancer that is about 1 1/2 to 2 times that of women with average breast density. Unfortunately, dense breast tissue can also make it harder to see cancers on mammograms.

A number of factors can affect breast density, such as age, menopausal status, the use of certain drugs , pregnancy, and genetics.

To learn more, see our information on breast density and mammograms.

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What Are My Options If I Have A ‘cancer Gene’

Women in high-risk categories and those who have the genes linked with breast cancer should consider starting regular breast cancer screening at age 25, or 10 years earlier than the age of the youngest relative with breast cancer at the time of their diagnosis.

Get to know how your breasts look and feel. If you notice any changes, see your doctor right away. And talk with your doctor about blood tests, pelvic exams, and transvaginal ultrasound to look for ovarian cancer.

Some women choose to have a preventive mastectomy to lower their chances of breast cancer. Itâs also possible to have your ovaries and fallopian tubes taken out. This doesnât get rid of all risk, but it does significantly lower it.

Another approach includes using anti-estrogen drugs:

  • Tamoxifen, useful in premenopausal and post-menopausal women
  • Raloxifene , used to treat osteoporosis useful only in post-menopausal women
  • Exemestane , an aromatase inhibitor useful only in post-menopausal women

Does Someone Who Inherits A Cancer Susceptibility Variant Always Get Cancer

Overview of Developments in Breast Cancer — Sloan-Kettering

No. Even if a cancer susceptibility variant is present in a family, it does not necessarily mean that everyone who inherits the variant will develop cancer. Several factors influence whether a given person with the variant will actually develop cancer. One is the penetrance of the variant. When not all people who carry a variant go on to develop the disease associated with that variant, it is said to have incomplete or reduced penetrance. Hereditary cancer syndromes can also vary in their expressivitythat is, people who inherit the variant may vary in the extent to which they show signs and symptoms of the syndrome, including the development of associated cancers. Lifestyle factors and environmental risks can also influence disease expression.

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Why Are Tumor Marker Tests Used

Along with other tests, tumor marker tests can help doctors diagnose cancer and recommend a treatment plan for an individual. Why, when, and how often these tests are done varies greatly from person to person. Rarely, they are used to help screen for a particular type of cancer in people with a high risk of the disease before they have signs and symptoms. But doctors mainly use tumor marker tests to:

  • Figure out how well a treatment is working

  • Predict a persons chance of recovery

  • Predict how likely it is a cancer will come back after treatment and find it if it does

How To Get Brca Genetic Testing

Genetic counseling is recommended for those who are interested in being tested for breast cancer gene mutations. You can talk to a doctor about getting a referral to a genetic counselor, who can help determine whether genetic testing would make sense based on family history and risk factors. Since many genetic tests only look for one specific gene mutation, the counselor can often help determine which mutations to test for.

The genetic test itself simply involves taking a small sample of blood or saliva, which is sent to a lab for analysis. Results can take several weeks or months.

Genetic testing results are not always clear-cut:

  • A test result can be positive, meaning that the patient does carry the gene mutation.
  • A negative test result indicates that they do not have that particular known gene mutation. It does not, however, rule out the possibility of having mutations in other genes. It also does not rule out the possibility of developing breast cancer. Most breast cancer cases are not hereditary, so everyone should still have an early detection plan.
  • Genetic test results can also be uncertain or ambiguous. An ambiguous test result means that a mutation has been found on the gene, but it is not yet known whether that particular mutation has any effect on the chances of developing breast cancer.
  • Someone is either negative or positive. Over time, a person cannot go from being negative to being positive or vice versa for the specific gene mutations they were tested for.

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What Do Brca1 And Brca2 Genetic Test Results Mean

BRCA1 and BRCA2 mutation testing can give several possible results: a positive result, a negative result, or a variant of uncertain significance result.

Positive result. A positive test result indicates that a person has inherited a known harmful variant in BRCA1 or BRCA2 and has an increased risk of developing certain cancers. However, a positive test result cannot tell whether or when the tested individual will develop cancer. Some people who inherit a harmful BRCA1 or BRCA2 variant never develop cancer.

A positive test result may also have important implications for family members, including future generations.

  • Both men and women who inherit a harmful BRCA1 or BRCA2 variant, whether or not they develop cancer themselves, may pass the variant to their children. Each child has a 50% chance of inheriting a parents variant.
  • All blood relatives of a person who has inherited a harmful BRCA1 or BRCA2 variant are at some increased risk of having the variant themselves. For example, each of that persons full siblings has a 50% chance of having inherited the variant as well.
  • Very rarely, an individual may test positive for a harmful variant not inherited from either parent. This is called a de novo variant. Such a variant is one that arose in a germ cell of one of the parents and is present in all the cells of the person who grew from that cell. The children of someone with a de novo variant are at risk of inheriting the variant.


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