Some 5 percent to 10 percent of all breast cancer cases - about 16,000 new cases a year - are likely due to an inherited mutation of two breast cancer genes known as BRCA1 and BRCA2. Everyone has these two genes. When they mutate, they greatly increase the chance of several types of cancer developing in men and women. Some, however, never develop cancer.
Men and women with a BRCA mutation have a 1 in 2 chance of passing the chromosomal abnormality to their children, whereas people without it cannot.
A positive test means a person has the mutation. A negative test result shows they do not. Tests often are covered by insurance, including those with Medicaid coverage who meet the plan's criteria.
Testing may cost as much as $4,000 - unless a mutation already has been discovered in a family. Then, costs drop to about $400 because it's easier to find a mutation once a precise chromosome has been identified.
Families with these gene mutations often have:
Many cancer cases in a family, especially breast or ovarian cancer.
One or more family members diagnosed with cancer before age 50 or relatives with several different types of cancer.
Male breast cancer or clusterings of colon, prostate, stomach or pancreatic tumors.
Any family relative who is of Ashkenazi Jewish descent and who has relatives who have had breast or ovarian cancer.
If you have those problems in your family, ask your physician about being tested for the gene and find out if the hospital he or she is affiliated with has a high-risk clinic or certified genetic counselors.
IF YOU HAVE THE GENETIC MUTATION
Carriers have the option of watchful waiting and tests; preventive strategies, also known as prophylactic surgery and chemotherapy; and what are called chemoprevention drugs, such as Tamoxifen, to lower the risk of cancer. Preventive surgery includes removal of the breasts or possibly of the ovaries and fallopian tubes.
Removal of both breasts lowers a woman's risk of developing breast cancer by as much as 90 percent, and removal of ovaries and fallopian tubes reduces the risk of ovarian cancer by 54 percent. Tamoxifen lowers a woman's breast cancer risk by 50 percent.
Carriers all are encouraged to:
Do breast self-exams beginning at age 18 and have exams performed by doctors starting at age 25, or 10 years before the youngest person in a family was diagnosed with cancer.
Have mammograms and breast magnetic imaging resonance (MRI) tests alternating every six months. Women who aren't finished with child-bearing should undergo semi-annual ultrasound tests and an ovarian cancer blood test, called CA125, beginning at ages 25-30.
WHERE TO GO FOR HELP
Many large hospital systems have counselors specializing in cancer genetics, and several have clinics for people at high risk of developing breast or ovarian cancer because they carry a genetic mutation.
Young Survival Coalition, a group of young women with breast cancer, www.youngsurvival.org.
State and federal laws protect consumers from health insurance discrimination based on genetic information.
Insurers can ask for proof of genetic information before they make payment decisions about tests and treatments, but they can't use that knowledge to deny you insurance.
For details about national laws, go to www.geneticfairness.org