Breast and Ovarian Cancer: What the Genetic Link Means
Breast cancer and ovarian cancer are different diseases, but they can sometimes be connected through inherited genetic changes. One of the best-known examples involves the BRCA1 and BRCA2 genes.
These genes normally help repair damaged DNA. Certain inherited harmful changes in BRCA1 or BRCA2 can increase the risk of developing breast, ovarian, and some other cancers.
That does not mean that everyone with a BRCA change will develop cancer, and most breast and ovarian cancers are not caused by inherited BRCA mutations.
Why Family History Matters
Your family history can provide clues about whether an inherited cancer risk might be present.
Doctors may pay particular attention when a family has several relatives with breast cancer, ovarian cancer at any age, breast cancer diagnosed at a younger age, cancer in both breasts, male breast cancer, or a known BRCA mutation. These patterns can occur on either your mother’s or father’s side of the family.
That’s why it is useful to know not only who in your family had cancer, but also what type of cancer and approximately what age they were diagnosed.
What Does a BRCA Link Actually Mean?
Having a harmful BRCA1 or BRCA2 variant means a person has a higher-than-average risk for certain cancers. It does not mean cancer is inevitable.
BRCA changes can be inherited from either parent. If a parent carries a harmful BRCA mutation, each child has a 50% chance of inheriting that particular mutation.
Other genes can also contribute to hereditary breast and ovarian cancer risk, which is why genetic evaluation may sometimes involve a panel looking at multiple genes rather than BRCA1 and BRCA2 alone.
Questions to Ask Your Doctor
If breast or ovarian cancer runs in your family, consider asking:
- Does my family history suggest that I may have an increased hereditary cancer risk?
- Should I see a genetic counselor?
- Would genetic testing for BRCA1 and BRCA2 make sense for me?
- Should testing include other cancer-related genes as well?
- Who in my family would be most informative to test first?
- If I test positive, what would that mean for my cancer risk?
- Would my screening schedule need to change?
- What would a negative result actually tell me given my family history?
- What does a “variant of uncertain significance” mean if it appears on my report?
- What information should I share with relatives?
Genetic counseling can help explain the potential benefits, limitations, and implications of testing before you decide whether testing is appropriate.
Bring Your Family History
Before your appointment, write down relatives who have had cancer, including both maternal and paternal relatives when possible. Record the type of cancer and approximate age at diagnosis.
Even information that seems unrelated can be useful. A genetic counselor can help determine which parts of the family history are important for assessing hereditary risk.
If a relative has already had genetic testing, obtaining a copy of the actual report can also be valuable because knowing the specific genetic variant can affect how other relatives are tested and how results are interpreted.
The Bottom Line
The breast-and-ovarian cancer connection does not mean that having one cancer automatically causes the other. Rather, certain inherited genetic changes—particularly harmful changes in BRCA1 and BRCA2—can increase the risk of both.
A family history is a reason to ask questions, not assume a diagnosis. If several relatives have had breast or ovarian cancer, especially at younger ages or in patterns associated with hereditary cancer, discuss your history with a healthcare professional and ask whether genetic counseling or testing is appropriate.