Breast cancer genetic markers: Testing not for all

Arguments for and against screening

Being proactive about health has gained lots of attention from consumers as well as health care providers, and testing for certain risk factors is part of that proactive approach.

But as much as women might want to know their risk of breast cancer, and even though there is lots of information on-line and in print about testing for mutations of the genes BRCA1 and BRCA2 (for BReast CAncer 1 and 2) as indicators of risk for breast cancer, the tests aren’t for everyone.

"There are certain women who we recommend should get the information on testing so they can make an informed decision, but there are arguments for and against screening and testing, and it’s not real clear cut," says Debbie Saslow, PhD, director of breast and cervical cancer control for the American Cancer Society (ACS) in Atlanta.

Family history influences risk

According to the National Cancer Institute (NCI), 5% to 10% of the 192,000 American women diagnosed each year with breast cancer have inherited forms of the disease, some of which are caused by inherited alterations of the BRCA1 and BRCA2 genes. The likelihood that breast and/or ovarian cancer is associated with BRCA1 or BRCA2 is highest in families with a history of multiple cases of breast cancer, cases of both breast and ovarian cancer, one or more family members with two primary cancers (original tumors at different sites), or an Ashkenazi (Eastern European) Jewish background.

However, the ACS and NCI caution that not every woman in such families carries an alteration in BRCA1 or BRCA2, and not every cancer in such families is linked to alterations in these genes.

"We’ve defined as high risk, women whose close relatives had breast cancer at an early age, or their mother had ovarian cancer, or a male relative had breast cancer, or a relative had bilateral cancer, as factors that would make you very suspicious that something genetic is going on," says Saslow. Adoptions and mostly male families can lessen the historical information a woman has, she notes.

It’s a given that some women who have one or more risk factors never get breast cancer, while others with no risk factors do get cancer.

But when is it advisable to recommend to a patient, or support her desire for, genetic testing for genetic mutations?

According to Jessica B. Mandell, MS, CGC, a genetic counselor and research coordinator for the New York Breast Cancer Study, which focused on Ashkenazi Jewish women with breast cancer, the first steps are a family history and medical risk assessment, and possibly genetic counseling. Men, too, who have the altered BRCA1 and BRCA2 genes are at greater risk for breast and other forms of cancer.

Cost and how to pay for the testing, which can run hundreds of dollars, is a big issue for some patients. There is controversy over what level of confidentiality a patient can expect, and what will happen if her insurer finds out that there has been a test that could reveal a predisposition to cancer.

If a patient is a candidate and has the testing performed, knowing what to do with the results is the next challenge for her and her physician.

Benefits to positive and negative results

While a negative result brings the relief of knowing that the patient’s risk is probably no greater than that of the general population for inherited cancers, even a positive test can carry some benefits.

An individual who receives a positive result is able to take steps to reduce other cancer risk factors, make informed decisions about the future, participate in clinical trials, and ensure proactive health monitoring is kept up so that if cancer does develop, it’s caught quickly.

Obviously, the clinician must be attuned to the impact a positive BRCA test will have on the patient’s emotions, relationship, and medical choices. Anxiety, depression, and anger are just a few typical reactions. A patient may react by seeking prophylactic mastectomy, for example, before any signs of cancer have arisen. Marriage, childbearing, and other life decisions may be affected.

Negative test results can cause feelings of guilt — for example, in a woman who tests negative for the BRCA gene after her mother and sister have endured cancer. Negative results also can lead to a false sense of reassurance against ever developing cancer.

Positive results can raise issues of privacy and confidentiality, particularly when it comes to insurance coverage.

People covered under employers’ group health coverage are protected under the Health Insurance Portability and Accountability Act (HIPAA) against loss or denial of coverage to someone who does not currently have a disease; however, the protection does not extend to personal insurance coverage, and insurers are not prohibited from asking for genetic background information. Patients who are covered by employers’ insurance when the tests are performed and who later leave their employment or otherwise seek new insurance coverage might be denied.

Since 2000, 41 states have enacted legislation related to discrimination in health insurance, and 31 states have adopted laws regarding genetic discrimination in the workplace. However, protections vary from state to state; patients contemplating genetic testing should be advised to seek advice on the laws and protections in their states.

As with screens done on newborns for inborn conditions, someone who deliberately withholds information about a disorder from an insurance company from which he or she is seeking coverage could be guilty of insurance fraud, but disclosure of the information could lead to lost coverage.

Testing children not advised

Saslow says screening children for the BRCA gene mutations is "absolutely not recommended."

"When you do this test, even if the result is positive, it doesn’t mean you’ll get cancer, and to have that on a 5-year-old would never be recommended," she says. "The average age is still postmenopausal, and most women who have breast cancer catch it early and they survive."

Likewise for genetic testing of unborn baby girls, she says.

"Most people don’t feel they would abort a baby with the gene," she says, eliminating the need to test before birth.

Sources

  • Debbie Saslow, PhD, Director of Breast and Cervical Cancer Control for the American Cancer Society, Atlanta. Phone: (800) 227-2345.
  • Jessica B. Mandell, MS, CGC, Genetic Counselor and Research Coordinator for the New York Breast Cancer Study, Sarah Lawrence College. Phone: (732) 651-1094. E-mail: jmandell@slc.edu.
  • National Cancer Institute, "Genetic testing for BRCA1 and BRCA2: It’s your choice." Available on-line at http://cis.nci.nih.gov/fact/3_62.htm.