Genetic Testing

To test or not to test?  That is the question.  If you have been diagnosed with breast cancer and have a strong family history, you ought to give it some thought.  For many, honing in on our DNA is a bit ‘over the top’ and seriously uncomfortable. For others it can be life saving information. As information is power, this genetic testing section has been added to the site to help you navigate this question for yourself.

MY GENETICS TESTING STORY

After diagnosis a few red flags were raised by a survey given to me by my breast surgeon about the possibility of ‘other’ caner.  My mind was suddenly overwhelmed with the idea of knowing or not knowing if I was BRCA-1 or 2 positive. Albeit, there is not a right answer to whether or not anyone should be tested.  As part of our discernment, Scott (Genetics Counselor) asked specific questions about both sides of our family.  Since defective genes come from either your mother or your father, it is important to evaluate the family tree, looking at the women in your family to spot abnormally high occurrences of breast cancer that may indicate testing would be advisable. Since my mother had breast cancer and we have a herd of boys in our family (no help to give me more information), my husband and I opted to have the BRCA-1 and BRCA-2 testing performed.  I did these simple blood tests at Delnor Community Hospital (now Cadence) through Scott.  Luckily, my insurance covered the tests.  Some insurance companies will not cover them, so that is a serious consideration as the tests can get pricey.

The timing of the testing for me was critical.  The blood tests were done in February 2011 shortly after my mastectomy.  I did not undergo immediate reconstruction for a number of reasons.  Getting the results of my genetic tests back was one of those reasons.  If either test were positive, I would give serious consideration to removing my other breast and my ovaries (as I would then have a 27-44% chance of developing ovarian cancer).  Luckily for me, like the majority of those tested, my results were negative.  At least these two tests.

Scott came to our Living Well Cancer Resource Center Mastectomy Support group this week to answer questions about genetic testing and to announce two new national research studies underway.  A research tab is now added for this site where you can look over any current research underway and opportunities to participate.

I plan to interview Scott, but in the meantime, here is information from the Delnor Center for Breast Health to get you started.

Breast Cancer Gene

In the past few years, scientists have discovered two genes, known as the BRCA1 and BRCA2 genes (BR=breast, CA=cancer), that place women who carry these genes at extremely high risk for developing breast and ovarian cancer and, to a much lesser degree, pancreatic cancer. Genetic testing for these genes was falsely publicized as the “test” for breast cancer. However, in reality, genetic testing for BRCA1 and BRCA2 only indicates that an altered (mutated or changed) cell exists, putting the carrier at a very high risk for cancer development. The test is only appropriate for a small number of women and men and not the general public. It is estimated that these mutated genes cause only about 7 to 10 percent of breast cancers.

Mutated Breast Genes Inheritance

Everyone is born with two copies of about 100,000 different genes. One copy of each gene comes from your mother and the other comes from your father. These genes are where hereditary breast cancer begins. When a person inherits a mutated (defective) gene from a parent, this causes them to be at very high risk to have breast or ovarian cancer in their lifetime. It was once believed that breast cancer risks came from only the mother’s history. We now know that half of all women with a hereditary breast or ovarian cancer inherited their risk from their father, not their mother.

A man or woman can inherit and carry a BRCA1 or BRCA2 mutation without ever developing cancer. This may cause the disease to skip a generation. It was once thought that a higher number of relatives with breast cancer was the most important factor; however, we now know that there are other important variables to identify a hereditary pattern. Strong clues for hereditary cancer are an early age of appearance for breast cancer with a high incidence of second breast cancers and ovarian cancer at any age, often appearing over several generations in the same bloodline. Family history may also have male breast cancer, prostate cancer, and pancreatic cancer.

Who is at Greater Risk?

A higher mutation incidence of BRCA1 and BRCA2 gene mutations is found in Ashkenazi (from eastern and central European descent) Jewish women. It is estimated that one in forty Jewish women carry a BRCA mutation. Two of these mutations have been found on BRCA1 and one on BRCA2. Because of knowing the exact location of the defective genes for this race, a special test call Multisite 3 BRC Analysis can be ordered. For the general population, over 100 variations of BRCA1 and BRCA2 have been identified that necessitate a more extensive testing procedure.

Your children are at a 50 percent risk of inheriting the altered gene if you are a carrier. Fathers may be carriers of the mutated gene and pass it on to their daughters and sons. Many risk assessment tools only look for cancer on the mother’s side of the family, overlooking hereditary breast cancer that is equally inherited from the father’s gene pool.

Statistics

Women who inherit the BRCA1 or BRCA2 gene have a 56 to 87 percent risk of developing breast cancer by the age of 70. They also have a 27 to 44 percent chance of developing ovarian cancer. Men who have the gene have an increased risk for prostate cancer and breast cancer. There is also an increased risk for both men and women of developing pancreatic cancer. For women who carry the BRCA1 gene and have breast cancer, there is a 20 percent chance of developing a second breast cancer within five years of their first cancer. With the BRCA2 gene, she faces a 12 percent chance of a second breast cancer within five years.

Testing for Hereditary Breast Cancer

A blood test can determine whether you are a BRCA1 or BRCA2 gene carrier. The ideal person to test is the person who has had breast cancer. The need to have a hereditary risk assessment must first be evaluated by a trained professional medical team. If your evaluation determines you are a candidate, counselors will discuss the advantages, disadvantages, and limitations of testing with you. At this time, you will be given an opportunity to decide if you wish to further pursue testing. Testing consists simply of having several tablespoons (30 ccs) of blood drawn from your arm and sent to a laboratory for analysis.

Who Is A Candidate For Genetic Testing?

The criteria for being tested for the BRCA1 or BRCA2 gene is based on your family history or personal degree of risk.

Testing is now performed for:

  • Person with breast and/or ovarian cancer who has two or more first-* or second-degree* blood relatives (on one side of family, maternal or paternal) with either breast or ovarian cancer.
  • Person with breast and/or ovarian cancer who has one first- or second-degree* blood relative younger than 45 (some authorities say 50 years of age or pre-menopausal) with breast cancer and/or ovarian cancer at any age.
  • Person with breast and/or ovarian cancer developed before age 45 (some authorities say 50 years of age or pre-menopausal).
  • Person with breast and/or ovarian cancer that is bilateral (both sides) or has multiple primary sites of cancer.
  • Males who develop breast cancer.
  • Blood relative (first- or second-degree relative*) who is documented as being a BRCA1 or BRCA2 gene carrier. *Definition of First- and Second-Degree Relatives
  • First-Degree: mother, father, sister, brother, daughter, son
  • Second-Degree: aunt, uncle, grandmother, grandfather, granddaughter, grandson, niece, nephew, half-brother, half-sister

Genetic Testing Exclusions

  • Person under 18 years of age
  • Cognitively impaired person, unable to give informed consent
  • Psychologically impaired according to professional evaluation

Benefits of Testing for Breast or Ovarian Cancer Risks

A test result of positive identifies you as a carrier. Therefore, you would be carefully monitored to ensure that if you develop the disease it is caught in the earliest stages when it can be most successfully treated. You would also be in a position to alter some potentially harmful lifestyle choices. For example, smoking should be stopped, alcohol intake reduced, exercise on a regular basis, and eat a healthy diet. If you are a young woman, planning your childbearing at a younger age minimizes your risk. Physicians are able to plan treatment protocols to prevent and/or detect other cancers. You would have the option to enter clinical trials or receive drugs to reduce your chance of the disease. Other family members may choose to be tested or placed in high-risk surveillance programs for early detection.

A negative test would relieve your anxiety about being a carrier and prevent unnecessary and expensive surveillance tests.

To Test or Not Test?

The decision to have genetic testing should be made in partnership between you and a professional treatment team who:

  • Evaluate your risks
  • Determine whether you meet criteria for testing
  • Offer you professional psychological counseling before and after the test results
  • answer all of your questions about the process
  • provide written information on the test and lab performing test
  • obtain informed consent for testing
  • protect your confidentiality
  • develop a surveillance/treatment plan after testing

Additional information about BRCA1 and BRCA2 genes.

Negative Test Result

If you receive a negative diagnosis from your test for hereditary breast cancer for the BRCA1 and BRCA2 gene mutations, your present risk for breast cancer is based on your family and personal health histories. Most often this puts most women back to the normal population risk and screening guidelines recommended by the American Cancer Society. However, some women because of their family or personal history will be negative for the gene but still be considered high risk and have increased surveillance for breast cancer recommended. Your healthcare team will discuss your present estimated risk and make recommendations for future screening.

Positive Test Result

If the test results were positive for BRCA1 or BRCA2 gene mutations, your healthcare provider will discuss opportunities and options to prevent or detect the cancers early. Authorities in cancer treatment have made recommendations to reduce the risk of the cancers that include increased surveillance, chemoprevention, and surgery. A brief options overview will prepare you to discuss your future care with your healthcare team.

When diagnosed with a positive mutation in either the BRCA1 or BRCA2 gene, decisions will need to be made about surveillance, risk reduction, or surgical options. Each option has advantages and disadvantages to consider. These are not easy decisions. Your physicians will discuss the above options. Talking with an experienced counselor will be helpful in evaluating the impact of the options on your individual lifestyle and personal goals.

Increased Surveillance

  • Breast self-exam: monthly starting by age 18 to 21
  • Clinical breast exam: annual or semi-annual starting by age 25 to 35
  • Mammography yearly beginning between the ages of 25 and 35
  • Consultation with a breast specialist provider when any change is detected
    Ovaries: Currently there is no proven screening test for ovarian cancer, but patients not desiring surgery may consider the following options:
  • CA-125 serum tumor marker testing annually or semiannually beginning at age 25 to 35
  • Transvaginal ultrasound starting between ages of 25 and 35 every 6 to 12 months
  • Clinical vaginal examination starting between age of 25 and 35 every 6 to 12 months

Surgery

  • Bilateral prophylactic mastectomies before age of 40 to reduce risk of breast cancer to the lowest level. (Note: breast cancer can still occur on the chest wall because only about 90% of the tissue can be removed from the chest. This also reduces the risk to the lowest level possible.)

Ovaries

  • Bilateral prophylactic oophorectomy by age 35, or after childbearing, to reduce the risk of ovarian cancer. This reduces the risk of both breast and ovarian cancer. (Note: ovarian cancer can still occur on the lining of the abdominal cavity from the cells that are left after surgery. However, this reduces the risk to the lowest possible level.)

Chemoprevention (hormonal therapies)

Breasts

Chemoprevention or hormonal therapy (SERMs) such as tamoxifen reduces the risk of breast cancer in high-risk women. The risk reduction in other high-risk groups is about 50%, but the percent reduction in BRCA mutation is not known.

Ovaries

  • Oral contraceptives greatly reduce the risk of ovarian cancer.

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