More than 15.5 million Americans are living with cancer, many of whom may have had a family history of the disease and genetic risk factors before they were diagnosed. Having a close relative with cancer doesn’t mean you’re going to be diagnosed yourself, but understanding the role family history and genes play in determining your risk can help you make more informed decisions about hereditary cancer prevention.
Let’s get into what you need to know.
Family History, Genetics and Cancer Risk
There are two kinds of risk factors for cancer: modifiable and nonmodifiable. The first kind is everything you have a say in, like your diet. The second kind refers to all the factors you can’t control, including your age, family history and genetics. Fortunately, hereditary causes make up a small portion — 5 to 10 percent — of all cancer cases.
Several components are involved in assessing a family medical history. Close family members often share similar environments and behaviors that can increase your cancer risk. If your entire family smokes or has a poor diet, for example, it’s more likely that you do, too. Gene defects or mutations that affect how cells normally function can also be passed down from a parent, increasing the cancer risk for their children and grandchildren.
This part gets a little complicated, however. When it comes to inherited gene mutations, having a first-degree relative like a parent or sibling with cancer is generally more concerning than having several distant relatives with cancer. The types of cancer in a family may also differ, so several cases of a rare cancer throughout your family may be more concerning than different cases of more common forms of cancer, such a breast cancer, melanoma or colon cancer. That’s why it’s critical to talk to your doctor to understand what you should do if you have a family history of cancer.
Cancer Screening and Genetic Testing
If you have a history of cancer in your family, your doctor may suggest early or additional screenings. People with an average risk for colon cancer should begin screening at age 45, but if you have a strong family history, you might need to start before then. Breast cancer screenings follow the same principle: If you have a high risk due to family history, the American Cancer Society recommends yearly mammograms with an MRI beginning at age 30. While all of this is good to keep in mind, though, don’t make any decisions about your health without chatting with your doctor first about what screening plan will benefit you the most.
If you have a particularly strong family history, you might also consider genetic testing. Genetic testing collects a risk assessment based on your medical and family history, plus cells from your blood, urine or other sources and gives you back a list of potential gene mutations to keep on your radar.
Now, undergoing genetic testing is a very personal decision. Seeing the result that you may have a high risk of cancer can cause some people to worry more than they need to, and at that point the test isn’t helping you — all it’s doing is stressing you out. Don’t opt for genetic testing unless you understand that these tests don’t indicate with any degree of certainty whether you will actually get cancer, and that they’re only meant to help you better understand your risk.
Hereditary Cancer Prevention: How to Reduce Your Risk
If you do undergo genetic testing and discover that you have a high cancer risk, nothing’s a done deal since there are ways to reduce your risk. Your doctor may suggest lifestyle changes like quitting smoking and losing weight, as these are two modifiable cancer risk factors.
Early detection can help, too, which is why it’s important to develop a screening plan if you have a family history. In some cases, preventive surgery — like a mastectomy to reduce breast cancer risk — may be an effective option. The key is to work with your doctor to come up with a game plan to reduce your risk and then follow it to the letter.
We’ve come a long way in diagnosing and treating cancer. Having a family history of cancer is nerve-wracking, but it doesn’t mean you’re actually going to get cancer. It’s just one factor, and you have so many tools in your arsenal to assess and reduce your risk.