Genetic Testing and DNA Banking
Genetic Testing, DNA Banking Benefit Survivors and Families
Cancer survivors, members of their families and anyone with a family history of cancer can now determine their risk for hereditary cancers that include (but aren't limited to) breast, ovarian and colon cancer.
The Swedish Cancer Institute's Hereditary Cancer Clinic opened at Swedish/First Hill in 2006 to provide counseling and genetic testing for people who have had cancer or may be at increased risk for cancer due to family history and genetics.
"If you're a cancer survivor and had a hereditary cancer — one that was caused by a mutated gene — then you are usually at increased risk to have another cancer in the same organ or in a different organ," says genetic counselor Roberta Resta, M.S., C.G.C.
Using breast cancer as an example, a survivor whose cancer wasn't hereditary has a 5 percent risk of developing a new, second breast cancer. If, however, the initial breast cancer was hereditary, as determined by family history and genetic testing, then there is a 30-40 percent chance of a new, second breast cancer developing.
The gene mutations that cause breast cancer also boost the risk of ovarian cancer to 40 percent, as opposed to a 2 percent risk in the general population. "Five percent to 10 percent of all women have hereditary risk factors for breast cancer," says Resta, "and there are a half-dozen genes that can lead to breast cancer. We can test for them all, if the tests are appropriate based on your history."
For other types of cancer — prostate and lung are examples, as is leukemia — there are no reliable genetic markers at the present time, nor are there any reliable screening tests to detect the cancers at an early and treatable stage. Research continues, however, with the goal of discovering more genetic markers and developing a new generation of screening tests.
DNA Banking for Any Type of Cancer
It is because of ongoing genetic research, as well as the genetic testing already available, that survivors of any kind of cancer may want to consider having their DNA banked. The Hereditary Cancer Clinic provides this service, which is not just for survivors whose cancer can already be identified with genetic markers.
"If you've had cancer and there are no current genetic markers, your family can use the DNA for testing down the road, when new genetic markers have been identified," says Resta. "DNA banking is one of the best gifts that you can give your kids and grandkids.
"This can help future generations accurately determine their risk, since mutated genes cannot skip a generation."
The results of genetic testing can indicate appropriate screening tests and medical procedures for anyone determined to be at risk of cancer. Oncologists, surgeons and other cancer specialists can also integrate the genetic-test results into surveillance for cancer and patient care.
For More Information
The Hereditary Cancer Clinic sees an average of about 50 patients a month, with the majority being cancer survivors or family members of cancer survivors. Each patient meets with a board-certified genetic counselor who reviews medical and family histories to determine which genetic tests are appropriate, and discusses the risks, advantages and costs of genetic testing for hereditary cancers.
The appointment usually lasts 30-90 minutes. Testing usually requires a simple blood draw with results usually taking about four weeks. All results are confidential.
The Hereditary Cancer Clinic is open Monday through Friday, from 9:30 a.m. to 3:30 p.m. Call 206-215-4377 for more information.