Family History Isn't the Whole Story

When someone close to you is diagnosed with breast cancer, your first concern is for them. Over time, you might start to worry about your own risk too. You may wonder if what happened to your mother, sister, or grandmother means it could happen to you. The answer is usually more hopeful than you might think. Having a family history of breast cancer is not the same as having an inherited risk gene, and knowing the difference can help you better understand your own health.

Factors like age, hormones, lifestyle, and things we can't control play a role. Only about 5 to 10 percent of breast cancers are linked to a gene change passed down from a parent. The best-known are BRCA1 and BRCA2, but others include PALB2, CHEK2, and ATM. Having a relative with breast cancer does not necessarily mean your family has one of these gene changes, and most people, it doesn't.

What Increases Risk

Not all family history affects your risk in the same way. For example, a great aunt diagnosed in her late seventies is different from a mother and sister who were both diagnosed in their forties. When our doctors at PCSRI review your family history, they look at how closely related you are to the person with cancer, with parents, siblings, and children counting most. They also consider how many relatives on the same side of the family have had cancer and how old they were when diagnosed, since breast cancer before age 50 can be more significant.

The things people worry about most can hold less weight than they seem. Having one distant relative with breast cancer, a few different cancers on both sides of the family, or a diagnosis that happened later in life are all common and usually do not mean there is an inherited gene involved. One of the best things you can do is talk with your family, write down what you find out, and bring that information to your next appointment. If your family history shows a pattern that needs more attention, your care team can help you decide if genetic counseling and testing are right for you.

If a Test Comes Back Positive

A positive genetic test result does not mean you have cancer. It means your risk is higher than average, which gives you the chance to plan ahead. Some people choose to have more frequent screenings, like breast MRIs along with mammograms, and may start these at a younger age. Others consider medications to lower their risk. Some decide on preventive surgery, either right away or later on, when it feels right for them and their family. Many people use a mix of these approaches or change their plans as life changes. There is no one right answer, and the choice is yours, with support from family, friends, and a team that understands your situation.

Your test result can also help your loved ones. Family members can choose whether they want to be tested, giving them the same opportunity to plan ahead. A negative result does not erase a strong family history. Your care team can still use your family information to recommend the best screening for you.

Your family's history is one part of your story, and it's worth understanding. It can guide the questions you ask and the choices you make, without deciding your future for you. At PCSRI, we're here to help you make sense of it, so you can shape the rest with confidence.