Relationship Between Breast and Ovarian Cancer: Key Linkages and Risk Factors
Breast and ovarian cancer – two of the most common cancers amongst women – aren't just close in terms of location; they've got a pretty tight relationship when it comes to their genetics too. Here's the lowdown on these twin terrors.
The connection between breast and ovarian cancer is largely genetic, particularly for those with mutations in the BRCA1 and BRCA2 genes. These genes play a crucial role in repairing DNA, and if they're mutated, the risk of developing both cancers skyrockets.
In fact, studies show that about 15% of families with a history of ovarian and breast cancer have BRCA1 gene mutations, while approximately 20% have BRCA2 mutations[1]. Astonishingly, these mutations can increase the lifetime risk of ovarian cancer by an alarming 40-60%, and breast cancer by a whopping 55-85%[2].
The genetic links don't stop there. If someone has had breast cancer, they may be twice as likely to develop ovarian cancer later on. Conversely, people diagnosed with ovarian cancer may have a 1.6-fold increased risk of subsequent breast cancer[2]. Genetics, it seems, is a tough taskmaster.
Other common risk factors for both cancers include:
- A family history of either cancer
- Increasing age (ovarian cancer tends to occur over the age of 40, while breast cancer becomes more common after the age of 55)
- Overweight or obesity
- Never carrying a pregnancy to full term
- Never breastfeeding
- Hormone therapy after menopause
It's worth noting that lifestyle changes can help offset some of these risk factors. Achieving and maintaining a moderate weight, regular exercise, and limiting alcohol intake have all been shown to help reduce the risk of breast and ovarian cancer.
If you have a personal or family history of these cancers, genetic testing for BRCA1, BRCA2, and other relevant mutations is essential. Your healthcare provider can help you navigate this complex process and discuss preventive measures, including prophylactic surgeries for those at high risk.
So, what's the catch? Well, as with any cancer, early detection is key to improving outcomes. If you've had breast or ovarian cancer before, it's crucial to stay vigilant for signs of recurrence or a second cancer. Regular screenings, such as mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, and CA-125 blood tests, can help detect these cancers in their early stages and increase the chances of successful treatment.
Looking ahead, a 2020 observational study suggests that people with both primary breast cancer and primary ovarian cancer have relatively favorable 5- and 10-year overall survival rates of around 90%. However, the outlook tends to be more positive when the interval between the two cancers is longer[3].
Finally, it's important to remember that while genetics may stack the odds, it's never a guarantee. Encouraging, supportive, and informed dialogue between patients, healthcare providers, and families is key in understanding the complex interplay of genetics, lifestyle, and environmental factors that contribute to cancer risk.
For more evidence-based information and resources on cancer, visit our dedicated hub.
[1] National Cancer Institute. (2020). Genetic Testing for Hereditary Breast and Ovarian Cancer. Retrieved from https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet
[2] Breastcancer.org. (2021). BRCA1 and BRCA2: What You Need to Know. Retrieved from https://www.breastcancer.org/recurrence/genes/brca1-brca2
[3] Wu, L., et al. (2020). Longitudinal Analysis of Survival and Proliferation among Patients With Both Primary Breast Cancer and Primary Ovarian Cancer. Journal of Clinical Oncology, 38(29), 3856–3864. Retrieved from https://ascopubs.org/doi/full/10.1200/JCO.19.02039
- The connection between breast and ovarian cancer is predominantly genetic, especially for individuals with mutations in the BRCA1 and BRCA2 genes, which are crucial for DNA repair.
- Approximately 15% of families with a history of ovarian and breast cancer have BRCA1 gene mutations, and around 20% have BRCA2 mutations.
- A mutated BRCA1 or BRCA2 gene can increase the lifetime risk of ovarian cancer by 40-60%, and breast cancer by 55-85%.
- If someone has had breast cancer, they may be twice as likely to develop ovarian cancer later on, and vice versa.
- Other common risk factors for both cancers include family history, increasing age, overweight or obesity, never carrying a pregnancy to full term, never breastfeeding, and hormone therapy after menopause.
- Lifestyle changes, such as achieving and maintaining a moderate weight, regular exercise, and limiting alcohol intake, can help reduce the risk of breast and ovarian cancer.
- Genetic testing for BRCA1, BRCA2, and other relevant mutations is essential for individuals with a personal or family history of these cancers.
- Regular screenings, such as mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, and CA-125 blood tests, help detect breast and ovarian cancers in their early stages, increasing the chances of successful treatment.
