Genes Predict Cancer Risk

Genes Predict Cancer Risk

Reported June 6, 2005

BOSTON (Ivanhoe Broadcast News) — About 9 million Americans are living with some type of cancer. Researchers say about 10 percent of cancer cases are genetic. Determining if cancer is in your genes could help you and your family members.

The Nash sisters have had some great memories. But cancer has brought some bad ones, too. These sisters lost a father, an aunt and three cousins to cancer. And two of them are breast cancer survivors. That bleak family history led them to genetic testing.

Genetic counselor Katherine Schneider, MPH, says tests can tell patients their risk of developing specific cancers by identifying defected genes. “It’s like looking for a misspelled word in a long book. They just go through page by page until they find something,” says Schneider, from Dana-Farber Cancer Institute in Boston.

Certain defected genes can triple a patient’s chance of developing some cancers. That may sound scary, but identifying those defects helps patients get earlier screening and make lifestyle changes. Schneider says: “It’s all about protecting them from getting diagnosed with advanced-staged cancer. That’s what this is all about.”

Schneider suggests genetic testing if three relatives on one side of the family had the same cancer, if a relative was unusually young when diagnosed, or if a relative had a rare type of cancer.

Even though two of the Nash sisters are breast cancer survivors, tests showed none of them had a defected gene — a result they consider a blessing. They hope that attitude brings them many years of happy memories.

Schneider says patients should undergo genetic counseling before a having a genetic test, which is a simple blood test. There are many different genetic tests for the different types of cancer. Schneider says most states have laws that prohibit health insurers from discriminating against clients who have a positive test result.