Cancer genetics: Know your family cancer history

When it comes to cancer genetics, learning about your family’s cancer history can help you learn about your own health.  It can even help determine if you may be at risk for an inherited cancers like breast, colorectal, ovarian, prostate or uterine cancer, which sometimes run in the family. 

Keep in mind that just a small portion of cancers – about 5 to 10% – are actually inherited. More cancers – about one-half – are related to lifestyle choices like smoking, not exercising and making unhealthy food choices.

Cancer genetics: Map out your family’s medical history

Here’s how to create your medical family tree.

1.Find out your ancestry. Include the countries where you ancestors came from originally. Some ancestries, like Ashkenazi Jews (Eastern European), have a higher risk for certain cancers.

2. List blood relatives. Include your first-degree (parents, siblings, children) and second-degree (nieces, nephews, aunts, uncles, grandparents) relatives. Add the current age of each or the age when they died.

3. Add cancer diagnoses, if any. Include the age when they were diagnosed with cancer, if you can find that out. List details, such as the part of the body where the cancer started and how the cancer was treated (chemotherapy, radiation therapy, surgery).

4. Include any birth defects or genetic disorders that you learn about.

Dig deeper for details

Hit a dead end while mapping out your tree? Try these tips to get more information:

• Speak with older relatives. They are usually good sources for information.
• Gather hospital records.

            -Hospitals can release records directly to the patient.

            -Has a relative died? Hospitals can release records to the next of kin, the closest relative entitled to the deceased individual’s property. 

Watch out for “red flags”

After completing your family tree, review your findings and look for these red flags.

1. Family member diagnosed with cancer before age 50.
2. Family member who has had two or more different cancers.
3. Two or more family members who have had the same type of cancer. Look specifically for breast, ovarian, colorectal, prostate or endometrial cancers.

If you find some of these red flags, speak with your doctor. He or she can help determine if you are at risk for hereditary cancer and may recommend that you speak with a genetic counselor.

A genetic counselor can help you decide if genetic testing is right for you. Genetic testing involves looking for abnormal genetic changes in a person’s blood sample.

Your doctor also can suggest changes you can make to prevent cancer, and the screening exams you need to find the disease as early as possible.

Make your family medical tree a priority this holiday season. It may help ensure that you enjoy many more holidays with your loved ones.

Karen Lu, M.D., is the J. Taylor Wharton Distinguished Chair in Gynecologic Oncology and Reproductive Medicine. 

Request an appointment at MD Anderson's Lyda Hill Cancer Prevention Center online or call 877-632-6789.

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