Genetic Tests Identify Cancer Risks
Journal Staff Writer, Monday, July 23, 2007
Jackie White doesn't have cancer, but she plans to undergo surgery this fall to remove her left breast and an ovary.
The 54-year-old grandmother and Albuquerque resident made her decision after a September 2006 test revealed that her genes contain a mutation that greatly increases her risk of developing breast and ovarian cancer.
"It's a peace-of-mind type issue," White said of her impending surgery at the University of New Mexico.
"Why walk around with a time-bomb in your chest? At this point in my life, it's just a practical decision to let it go."
More people are having genetic testing done.
UNM's Hereditary Cancer Risk Assessment Program has grown quickly since its launch in 2002. In 2006, the program tested 200 new patients, up from 56 in 2002, said Lori Ballinger, the program's certified genetic counselor.
The UNM program and Hemotology Oncology Associates of New Mexico are the only two oncology clinics in the state with formal programs for genetic cancer testing.
People who seek genetic testing often have had cancer and want to assess their risk of a second cancer, Ballinger said. Likely candidates are those who have a strong family history of the disease and have family members diagnosed at an early age.
White, a retired Air Force technical sergeant, fit that profile. She survived breast cancer and underwent a right mastectomy and had an ovary removed in 1983. Her mother died of ovarian cancer.
The program tests primarily for breast and ovarian cancer and some colon cancers, Ballinger said. Women comprise about three-quarters of those tested.
Cancer is caused by genetic mutations that cause cells to multiply uncontrollably.
Genetic mutations occur in individuals as people age. About 95 percent of all cancers result from these acquired mutations.
But about 5 percent of cancers are caused by mutated genes inherited from a parent, Ballinger said. In cases such as White's, such a genetic predisposition can drastically increase cancer risk.
White's test found a mutation in a gene called BRCA 1, or breast cancer 1. Mutations in BRCA 1 or a second gene, BRCA 2, heighten a woman's chances of developing cancer to 80 percent or more.
White said her report put her chances of developing breast cancer by age 70 at 87 percent and ovarian cancer at 44 percent.
An inherited genetic condition heightens the risk so dramatically because the mutated gene exists in every cell of the body, Ballinger said.
"If that's something going on in your family, the risk can be enormous," she said.
Racial prevalence?
Dr. Paul Duncan, an oncologist at Hemotology Oncology Associates who specializes in hereditary cancer, said the defective BRCA 1 and BRCA 2 genes appear to be prevalent among Hispanic women of colonial Spanish descent.
Duncan said he treats about 35 New Mexico families with the BRCA 1 or BRCA 2 defect.
But the true prevalence of the defect in New Mexico is unknown, he said. "It could be as high as 10 percent of Hispanic families of Spanish colonial descent," he said.
Undergoing surgery to minimize cancer risk is a practice called "prophylactic surgery." Patients react differently to the prospect of such surgery.
Dr. Melanie Royce, a University of New Mexico oncologist and one of the physicians on White's team, said she simply provides patients with risks and options and lets them decide.
"It's not something we tell patients they must do," Royce said. "It's her decision."
For people who don't want prophylactic surgery, the chief option is rigorous screening, such as the use of breast-MRI scans in addition to mammograms for detecting breast cancer, Royce said.
"Medically, there is not always a right or wrong answer," she said.
Duncan said he doesn't know how many people have received prophylactic surgery in New Mexico.
But of the 35 families he treats for the BRCA 1 and BRCA 2 defect, he said, at least one woman per family has received a prophylactic mastectomy.
Duncan said he also treats about 20 families with a gene that predisposes them to colon cancer. Some patients undergo a prophylactic colectomy, which removes a portion of the bowel, to reduce the likelihood of colon cancer, he said.
Genes with a genetic predisposition for cancer typically come to light when a member of the family develops cancer and doctors notice a strong family history of the disease, he said.
"When you begin to see ovarian and breast cancer sprinkled through someone's family, particularly in young people, that's usually a tipoff," he said.
Costs of testing
Most insurance companies will cover the cost of genetic testing, experts say.
Cost ranges from $400 to $4,000 depending on the test, Ballinger said. Testing for mutations in the two BRCA genes runs about $3,300.
Some people are reluctant to ask their insurance company to cover the cost because they fear insurers will cancel their policies or raise their premiums if the test reveals a potentially harmful mutation, Ballinger said.
But New Mexico law offers protections from "genetic discrimination" by insurance companies.
"I think people know that in the state of New Mexico, they're protected," Duncan said.
New Mexico lawmakers approved a measure in 2005 that prohibits insurance companies from considering genetic propensity for a disease as a pre-existing condition for limiting insurance benefits or setting premiums.
Rep. Danice Picraux, D-Albuquerque, who sponsored the legislation, said she is unaware of any case of someone losing insurance or paying higher rates as a result of genetic testing.
"I'm really protecting the person," Picraux said. "I want them to get insurance and afford insurance."
Both Duncan and Royce said they have heard no complaints about patients losing insurance or paying higher premiums as a consequence of testing.
What's your cancer risk?
You may be at risk for hereditary cancer if you answer yes to certain questions:
- Have you or a family member had cancer before age 45?
Has someone in your family had two different cancers?
Have two or more members of your family had the same type of cancer?
Have you or a family member had cancer in both of paired organs, such as breasts, eyes or kidneys?
Do you have both breast and ovarian cancer in your family?
- Do you have both colon and uterine and/or stomach cancer in your family?
-- SOURCE: University of New Mexico Hereditary Cancer Risk Assessment Program
