While some cancers do seem to run in families, it’s not always clear whether a particular cancer is caused by genetics or by something else, like lifestyle.
In fact, only about 5 percent to 10 percent of cancer cases can be traced to inherited genetic abnormalities. Often, cancers occur in families because they have similar habits or environmental exposures.
A family with many smokers, for instance, would have a higher than normal number of cancer cases in the family tree. Families who live in polluted environments may also have higher levels of cancer.
Still, certain types of cancers are associated with faulty genes that are passed down in families. Specific gene mutations have been shown to significantly increase one’s risk for colon, breast and ovarian cancer. Women who inherit breast cancer genes, for instance, have a very high risk for developing breast cancer before age 40.
Inheriting an abnormal gene is not the same thing as inheriting cancer. Genetic factors increase your risk, but you may still be able to avoid cancer by making lifestyle changes and monitoring your health closely.
To help you understand your cancer risks and minimize them, a good place to start is with your family history. Compile a list of close relatives and note which ones had cancer. Include the type of cancer or cancers they had, age of diagnosis, and whether they smoked. Then look for red flags that could indicate an inheritable genetic cause.
Examples of things to look when compiling a family history:
• Childhood cancer occurring in siblings
• Family members who had more than one type of cancer in their lifetime
• Cancer in both paired organs (both breasts or both kidneys)
• Several cases of rare cancers
• Cancers that usually strike older people occurring at younger ages
Keep in mind that cancers in close relatives are more worrisome than those in distant relatives. Also, multiple cancers occurring on the same branch of the family tree — on your father’s side or your mother’s side — are cause for greater concern.
Once you have pinpointed cancers that have occurred in close relatives, you and your doctor can map out a strategy for reducing your risk factors for those cancers. You may need to modify your diet, exercise more, or make other lifestyle changes. Your doctor may also want to start cancer screenings at an earlier age or perform screenings more often. In any case, you’ll want to learn more about cancer symptoms so you can take action at the first sign of the disease.
If your family history uncovers strong patterns of cancer, you may want to consider genetic testing to confirm whether you have any gene mutations.
Before seeking out genetic testing, it’s a good idea to talk to a genetic counselor about the pros and cons.
Putting together a family medical history takes time, but it can help you take control of your health for a better future.
Click here to read an article on H2U’s blog about where to start creating your family tree.
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