Genetic Testing: What You Need to Know

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What if genetic testing shows an increased cancer risk?

If your genetic test result is positive or inconclusive for a gene mutation that could increase your risk of cancer, managing the risk should become a priority.

Some of the ways you might lower your risk include taking medicines (called chemoprevention), having preventive (or prophylactic) surgery, and making lifestyle changes. Doing what you can to find cancer early (through testing and awareness of early signs and symptoms), when treatment is most likely to be successful, is also important for people at increased risk.

Your doctor may recommend one or more of these approaches, but it’s important to understand how much they could affect your risk before you decide on a course of action. You will also want to be sure you understand their risks and downsides before deciding on a plan.


Chemoprevention is the use of medicines to prevent cells from developing into certain types of cancer. Several medicines are being studied and used to help lower the risk of certain cancers in people known to be at high risk. For example, the drugs tamoxifen and raloxifene can be used to reduce breast cancer risk. Each person’s risk and medical situation must be considered carefully so that any harmful effects of the drugs do not outweigh the benefits. As we learn more about genetic diseases, we should find out more about using medicines to prevent cancer.

Prophylactic (preventive) surgery

Prophylactic (preventive) surgery is another option in some cases. For example, some women at high risk for ovarian cancer may decide to have their ovaries removed once they’ve had their children.

Changes in lifestyle factors

Ask your doctor if there are lifestyle changes you can make that could affect your risk, such as limiting alcohol intake and exercising to lower your risk of colon or breast cancer. In some cases the effect of these changes on risk might be small compared to the increased risk from the mutation, but you may still want to ask your doctor what you can do.

Cancer detection tests and awareness

Early detection tests may be started at an earlier age or be done more often, or special tests may be needed if you have a positive genetic test result. For instance, a person known to have an increased risk of colon cancer might need to start screening earlier than the usual age of 50. Likewise, a woman with a genetic mutation that raises her risk of breast cancer might need breast MRI scans along with her mammograms to look for early signs of the cancer.

It’s also important to be aware of the possible signs and symptoms of cancers you are at higher risk for, and to see a doctor right away if anything concerns you. Finding and treating cancer early offers the best chance of having a good outcome.

Sharing results with family members

If you have a gene mutation that raises your risk, there may be other factors to think about, too, such as whether to tell other family members who might also be at increased risk. Telling them might help them decide if they should get tested or adopt some of the approaches to try to lower their risk.

On the other hand, some test results may cause more anxiety than anything else, and some family members may not want to know their own risk. This is especially true if there’s not much they can do with the results. You may want to speak with family members before you get tested to find out if they want to know your results.

Last Medical Review: 10/18/2013
Last Revised: 03/11/2015