Wednesday, December 25, 2002

Cancer genes are inherited from both parents

Both sides of the family history are important in considering the genetic risk of breast and prostate cancers, says a genetics specialist at Baylor College of Medicine in Houston.

"The genes that cause these diseases are genes you inherit from both parents," said Dr. Sharon Plon, associate professor of molecular and human genetics and pediatrics at Baylor. "For a woman, if Mom's family has no history of breast cancer, but Dad has three sisters who were diagnosed with breast cancer, that's just as worrisome."

The same is true for prostate cancer, and other forms of cancer that are influenced by genetics.

"People tend to focus on the parent who is the same gender as they are. Women look at their mom's side for breast cancer and men look at their dad's side for prostate cancer, but this is missing half the story," she said.

About 10 percent of all cancers are in people who have inherited a predisposition to cancer. Genetics counselors assess those who might have an increased risk of cancer because of family history.

"Even if there is a history of cancer in your family, that does not necessarily mean you will develop the disease," Plon said. "But, it's important to determine if you are at an increased risk and may need early screening."

Families with a genetic susceptibility to cancer may have:

Multiple family members with the same cancers.

Family members who develop cancer at an unusually young age.

Family members who develop a second or third "new" cancer.

Family members with certain rare cancers, such as male breast cancer.

Plon said those who are concerned about an increased risk of cancer should discuss the issue with their primary care physicians. If a genetic evaluation is recommended, the individual will be provided a risk assessment, as well as suggestions for prevention, early detection and treatment options.