Genetic testing may be beneficial in identifying cancer cause

By Kelli Ameling • Last Updated 10:57 am on Tuesday, October 23, 2012

A sample of what is included in a BRCA testing kit. Courtesy photo

Jeffrey Bissonnette, certified genetic counselor at the cancer genetics program for Spectrum Health, works with patients who has either personal and/or family history that is suggestive of a hereditary cancer condition — a single gene running in the family greatly increasing the risk of cancer.

The main genes Bissonnette is concerned about when it comes to family history with breast cancer are BRCA1 and BRCA2.

“However, there are other genes that can increase a woman’s rick for breast cancer,” Bissonnette said. “In general, testing for genes related to breast cancer is best for individuals who are at an increased risk for having a genetic change — known as a mutation — in these genes.”

He said these are based on features observed in a patients personal or family history, and when one or more of the features are detected in a family, genetic testing may be beneficial in identifying if there is a single gene causing the cancer.

Genetic testings is usually started by testing someone in the family who has had the cancer, Bissonnette said, to help identify the cause of the cancer.

He explained if a mother is tested and has a mutation, the daughter than can be tested for it. However, if the mother does not have a mutation, the daughter is not at an increased risk.

“If you test her mother and she does not have a mutation, then these genes are unlikely to be the cause of cancer in the family,” Bissonnette said.

For women who has had or currently has cancer, testing may help determine why cancer was developed, he said, and could provide enough information to a women to help her make treatment decisions.

For women who have not had cancer, testing determines whether she has a genetic factor to put her at a higher risk, or if she does not have the factor, she would not be at a higher risk, he said.

“If a woman has a BRCA mutation, that doesn’t mean she will develop cancer but her risks are much greater,” Bissonnette said. “The lifetime risk for breast cancer is 50 to 80 percent and the lifetime risk for ovarian cancer is 10 to 45 percent.

“For those who test negative for a mutation that is in the family, that means they don’t have the above cancer risks but they are (at least) still at general population risk for developing breast and ovarian cancer — 12 percent and 1.5 percent lifetime risk, respectively.”

Bissonnette said the main downside to genetic testing  is whether a person wants to know, and what they do with the information.

For people with BRCA mutations, specific screenings and surgical options are available to them to help decrease their cancer risk, he said.

“There can also be concerns related to life insurance discrimination based on genetic test results,” he said. “There are federal law protecting individuals against health insurance and employment discrimination based on genetic testing results, but those laws do not apply to life insurance discrimination.”

Bissonnette said the cost for the testing is $3,340 for sequencing — finding errors in the genes — and $700 for the BART testing — finding large pieces missing from the genes.

“Most insurance companies will cover BRCA sequencing if the patient meets certain personal or family history criteria,” he said. “BART testing has been more difficult to obtain coverage for, except for some of the most high risk patients.”

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