If your family tree includes one or more relatives with a history of breast cancer, you probably know that you could be at increased risk for the disease, too.
Reason: About 5% to 10% of breast cancer cases are due to inherited genetic mutations. Women who carry one of these altered genes are at least five times more likely than average to develop breast cancer. They also are at increased risk for ovarian cancer.
A blood test can reveal whether you have one of the genes linked to breast cancer. Why might you want to know? Because learning that you do not have the gene reduces anxiety… and if you do have the gene, you can consider the options for lowering your risk.
Reassuring: By law, health insurance companies can no longer deny coverage or charge higher premiums based on a person’s genetic predisposition for developing a certain disease in the future… and employers cannot use genetic information when making decisions about hiring, promoting or firing personnel.
A first-degree relative is your parent, sibling or offspring. A second-degree relative is your grandparent, grandchild, half-sibling, uncle, aunt, nephew or niece. Consider genetic testing if you have or had any of the following…
A personal history of breast cancer or a biopsy that showed benign changes (such as atypical ductal hyperplasia or lobular carcinoma in situ), especially by age 50.
A first-degree relative who had breast cancer by age 50 or tested positive for a breast cancer gene.
Three or more first- or second-degree relatives with breast cancer, regardless of age.
A first-degree relative with ovarian cancer.
A first- or second-degree relative with cancer in both breasts… or with breast and ovarian cancer.
A first- or second-degree male relative who had breast cancer.
One first-degree relative or two second-degree relatives who had breast or ovarian cancer if you are of Ashkenazi Jewish, Dutch, Icelandic or Norwegian descent.
HOW TO GET TESTED
Most major hospitals have genetic testing programs.
Recommended: Consult a medical or surgical oncologist — a cancer specialist who can evaluate your overall risk, perform the test, discuss results, advise you on risk reduction and provide individualized follow-up care.
The doctor takes a complete family history to help you assess the advisability of testing. If you decide to go ahead, blood is drawn for analysis. Typically it takes several weeks to get test results.
The test looks at genes that belong to a class called tumor suppressors, whose role is to prevent uncontrolled cell growth. Most inherited breast cancers result from harmful alterations of the BRCA1 and BRCA2 genes. There also are other gene mutations linked to increased risk for a hereditary cancer syndrome, which can be assessed and tested for separately. In rare cases, a person carries more than one of the gene mutations linked to breast cancer.
WHAT YOUR RESULTS MEAN
Of course you’ll feel relieved if your test reveals no mutated breast cancer gene. But remember: You may have one of the other, less common hereditary cancer syndromes or a genetic mutation as yet unidentified, or you may develop a noninherited form of breast cancer — so it’s still important to have regular mammograms and pelvic exams.
If it turns out that you do carry a mutated breast cancer gene, this does not mean that breast cancer is definitely in your future. Women with such a gene have about a 40% to 85% lifetime risk of developing breast cancer and a 15% to 40% risk for ovarian cancer. They also may be at increased risk for cancer of the pancreas or colon and/or for melanoma.
Let this information empower you to take steps to minimize your risk. Your doctor can help you decide which of the following options might be right for you…
Increased surveillance. Additional and more frequent screening tests cannot alter your risk for getting breast cancer, but they can help detect a malignancy early, when it may be most treatable. Each year, get a mammogram and breast ultrasound together… get an MRI six months later. You also may be advised to have a transvaginal ultrasound and CA-125 blood test periodically, which may help screen for ovarian cancer.
Lifestyle changes. Do aerobic exercise for at least 20 minutes three or more times each week. Limit alcohol consumption to no more than three glasses of wine weekly. Don’t smoke. Maintain a healthful diet, and work with a dietitian to lose weight if necessary. Do not take menopausal hormone therapy — it increases risk.
Chemoprevention. The oral drugs tamoxifen and raloxifene block the effects of estrogen on breast tissue.
Encouraging: Among pre- and postmenopausal women at increased risk, tamoxifen reduces the likelihood of invasive breast cancer by 49%… raloxifene’s protective effects are similar for women past menopause. Typically the drug is taken once daily for five years.
Important: Work with your doctor to weigh the advantages against the disadvantages. Possible side effects include hot flashes, leg cramps, joint pain and increased risk for blood clots and/or uterine cancer.
Prophylactic bilateral (double) mastectomy. This surgical procedure removes as much breast tissue as possible. It reduces a woman’s risk by more than 95% (though not 100%, since some breast tissue cells may remain). Mastectomy can be combined with breast reconstruction.
Prophylactic bilateral salpingo-oophorectomy. Surgical removal of ovaries and Fallopian tubes lowers breast cancer risk in premenopausal women by about 50% because it greatly reduces hormone production. It also reduces ovarian cancer risk by 93%. (There is still a small risk for an ovarian cancer variant that arises in the abdominal lining.) This option should be discussed with a doctor who understands the risks and knows your family-planning goals.