Genetic testing may help find cancer

BALTIMORE - September is Ovarian Cancer Awareness month and next month starts Breast Cancer Awareness month.

It is extremely difficult to determine which women will develop, breast or ovarian cancer, but now for families with a history of these diseases, doctors and scientists are getting a little closer to pinpointing the causes.

More and more are using genetic testing.

So who should take advantage of this option and what are doctors looking for? Here's some common questions and answers from our friends at Cancer Treatment Centers of America (CTCA).

Who should be considering genetic testing?

Click to the next page to find out.

  • People who have been diagnosed with cancer and/or people who have a strong family history of cancer can consider genetic testing.
  • Red flags to consider are anyone in your family who developed cancer at a young age, multiple family members who developed cancer, if you've experienced bilateral cancer (cancer in both breasts), breast and ovarian cancer in the same woman, or cancer appeared where it wasn't expected (like breast cancer in men)
  • New National Comprehensive Cancer Network (NCCN) guidelines suggest BRCA (BRCA1 and BRCA2 are human genes that belong to a class of genes known as tumor suppressors) testing for any woman who has been diagnosed with ovarian cancer and for any woman who has been diagnosed with any type of breast cancer at age 45 or younger or with triple negative breast cancer at age 60 or younger.
  • CTCA doesn't test anyone under the age of 18 since these are adult onset cancers. If they know there is a mutation in the family they start testing women around age 25 and men before they're ready to start having children

What is the role of a genetic counselor?

  • At CTCA all of the patients have a diagnosis of cancer. Melanie Corbman says "I talk to the patients about their cancer history and the history of cancer in the family to decide whether it looks like the cancer in the family is something that is hereditary. I explain genetic testing and how it can be helpful for the patient and their family members".
  • Corbman says the "get the best answers from genetic testing if we do the testing in someone who already has been diagnosed with cancer."
  • For patients who already have a cancer diagnosis genetic testing can help determine some of their treatment decisions and options and if they are at risk for developing other cancers.
  • For their family members, the counselor will help them learn if they are also at risk of developing the cancer.
  • We get ½ of our genes from our mother and ½ of our genes from our father. We pass on ½ of our genes to each one of our children. If a person is found to have a BRCA mutation, each of their siblings and each of their children also have a 50/50 chance of having the same mutation.

How does genetic testing work?

  • It's a simple blood or saliva test that is then sent to a lab that does the genetic testing
  • The major genes that we know of that are involved in breast and ovarian cancer are the BRCA genes. In the 1990s the BRCA1 and BRCA2 genes were identified and they help protect us from breast cancer, ovarian cancer. If they are working properly they protect us. All men and women have these genes. Genetic testing tells us whether the genes are working properly to protect us from cancer or if there are changes in the genes called mutations that prevent the genes from working properly. BRCA1 and BRCA2 gene mutations put us at risk of getting these cancers.

What should people know if they test positive for any of these gene mutations?

  • Breast cancer is common in the general population. The average woman's risk for breast cancer is about 12% but a woman with a BRCA mutation can have up to an 85% risk of developing breast cancer. A woman who has already been diagnosed with breast cancer and who has BRCA mutation has a higher risk of getting a new breast cancer.
  • The average woman's risk of getting ovarian cancer is low, about 1.5% but a woman with a BRCA mutation can have up to a 50% risk of getting ovarian cancer. Women with a cancer diagnosis may want to be more aggressive with their treatment if they know they have a BRCA mutation and have a higher chance of getting cancer again.
  • Women who have never been diagnosed with cancer can protect themselves by screening for breast cancer starting at age 25 with mammograms, MRIs and physician breast exams. Screening for ovarian cancer around the same time with ultrasounds and blood tests. Since screening for ovarian cancer is not as effective in finding the cancer early, many women choose to remove their ovaries at age 40 if they are done having children.
  • Men who test positive for the BRCA gene mutations have a slightly increased risk of breast cancer and about a 25%, increased risk for prostate cancers. These men should start screening for prostate cancer at age 40.
  • Both men and women who have a history of pancreatic cancer in their families and have tested positive for a BRCA2 mutation may have an increased risk for pancreatic cancer.

Are there tests now available for other cancer types?

  • Other genes can also cause an increased risk of breast cancer
  • Ovarian cancer genes can also be part of hereditary colon cancer syndromes
  • Genetic testing available for thyroid and kidney cancers

If you have a family history of any of these cancers you should consider meeting with a genetic counselor.

You can find a local genetic counselor on the National Society of Genetic Counselors website www.NSGC.org

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