Genetic testing for breast cancer? Maybe. But first, counseling

October 29, 2013 | by

Since actress Angelina Jolie told the world about her decision to undergo a preventive double mastectomy due to a gene mutation that greatly increases her risk of developing breast cancer, many women have been wondering if they too should undergo genetic testing.

Genetic counseling for cancer is a multidisciplinary approach where genetic counselors work together to take care of patients who might be at high risk.

Genetic counseling for cancer is a multidisciplinary approach in which genetic counselors work with oncologists or geneticists to help patients at high-risk make informed decisions.

Genetic counseling can help answer that question, said Jeffrey Weitzel, M.D., director of the Division of Clinical Cancer Genetics at City of Hope.

“The practice of genetic counseling for cancer is a multidisciplinary approach where genetic counselors — who are masters trained individuals and trained to teach patients and families about genetics as well as getting a good family history — work together, usually with an oncologist or a geneticist, to take care of patients who might be at high risk,” said Weitzel in a recent interview with the Los Angeles Daily News.

In cases in which a close family member has had cancer, Weitzel recommends first testing that person to determine if she carries a specific mutation. That narrows the genetic search in the potentially at-risk relative.

“Now instead of the entirety of two genes — previously costing about $4,000 — you’re looking for just one spot on the gene because you know that’s where the mistake was,” Weitzel said in the interview. “It’s about one-tenth of the cost, and it’s informative because I know that abnormality is detectable, so now it’s either there or it’s not. So then the inclusion is correct, the woman did, or did not, inherit the abnormal copy that her mother or sister had. So now we know her steps.”

Inherited gene mutations that result in a very high risk of breast and ovarian cancer — including the BRCA1 mutation that Jolie carries — account for only about 5 to 10 percent of breast cancer cases, according to the National Cancer Institute.

Even people with a genetic history of breast cancer stand a 50 percent chance that they'll not inherit the relevant gene, Weitzel said.

And in any case, he doesn't recommend testing patients until they reach an age at which cancer is likely. For example, he said, he won't test a 16-year-old for the BRCA1 or BRCA2 mutations and will test a 25-year-old only if breast or ovarian cancer has developed at a young age in the family.

In assessing risk, all decisions are case-specific.

“Any time there’s a strong family history of cancer, when we talk to the surviving family members, for the women, it’s not a matter of if but when they are going to get cancer, from their own perception, Weitzel told the Los Angeles Daily News. “So we can choose the counseling to help them understand the circumstance, we can use the testing to try to identify their risk and if they do have high risk then we have lots of options to help them avoid repeating the story.”