Key takeaways

• Having relatives with breast cancer does not automatically mean you have inherited a cancer-causing gene change.
• The number of affected relatives, their relationship to you and the age at diagnosis can all matter when assessing family history.
• Genetic counselling and, where appropriate, genetic testing can help clarify whether an inherited risk may be present.
• Knowing your family history can help you and your doctor decide whether you may need a different approach to breast cancer screening.

Does breast cancer in my family mean I have inherited the risk?

Not necessarily. Breast cancer is common, and many people who have a relative with breast cancer do not carry an inherited genetic change that significantly increases their risk.

However, some breast cancers are linked to inherited changes in genes involved in protecting cells from becoming cancerous. BRCA1 and BRCA2 are two well-known examples, although other genes can also be involved.

The pattern of cancer in your family can provide important clues. For example, inherited risk may be considered more carefully when several close relatives have had breast or related cancers, particularly if someone was diagnosed at a younger age or if cancers have occurred in multiple generations.

What does my family history actually tell me?

When discussing your breast cancer family history with a doctor, it can help to look beyond simply asking whether anyone in the family had cancer. Some useful details include,

• Which relatives had breast cancer or other cancers
• Whether they are on your mother’s or father’s side
• Their age when they were diagnosed
• Whether anyone had breast cancer in both breasts
• Whether there have been cases of ovarian, pancreatic or certain other cancers in the family
• Whether anyone in the family has already had genetic testing

Both sides of the family matter. An inherited gene change can be passed down through either parent, so focusing only on your mother’s relatives may miss relevant information.

When might genetic testing be considered?

Genetic testing is not automatically necessary for everyone with a family history of breast cancer. A doctor may first assess your personal and family history to determine whether genetic counselling or testing could be appropriate.

Genetic testing looks for particular inherited gene changes. Depending on the circumstances, testing may involve a blood or saliva sample. The result may indicate that a specific inherited change was found, that no relevant change was identified, or that the result is uncertain.

Importantly, a genetic test result needs to be interpreted alongside your family and personal history. A negative result does not always mean that a person’s overall breast cancer risk is the same as someone without a family history.

What should I do if I am worried about my family history?

Start by gathering as much accurate family information as you can. If possible, ask relatives about cancer diagnoses and ages at diagnosis, and keep any previous genetic test reports that are available.

A doctor can then assess your individual circumstances and discuss whether genetic counselling, genetic testing or an appropriate breast screening plan should be considered.

Frequently Asked Questions

If my mother had breast cancer, would I get it too?

No. Having an affected mother can increase your risk compared with someone without that family history, but it does not mean that you will definitely develop breast cancer.

Can breast cancer be inherited from my father?

Yes. Inherited gene changes associated with breast cancer can be passed through either the mother’s or father’s side of the family.

Should everyone with a family history have genetic testing?

No. Whether testing is appropriate depends on factors such as your personal history and the pattern of cancers in your family. A medical assessment can help determine whether further evaluation is warranted.

What if genetic testing does not find an inherited gene change?

A negative test does not necessarily remove all increased risk associated with family history. Your overall risk still needs to be considered in context.

Can I still have breast cancer if there is no family history?

Yes. Breast cancer can occur in people without a known family history or identifiable inherited genetic risk.

Understanding your inherited risk

A family history of breast cancer is a reason to understand your risk, not a reason to assume the worst. The right assessment depends on the details of your personal and family history.

If you are concerned about inherited breast cancer risk, you can discuss your family history and screening options with Dr. Radhika Lakshamanan at Radhika Breast & General Surgery. An individual assessment can help determine what further evaluation, if any, may be appropriate for you.