Connection Between Breast and Ovarian Cancer: Implicated Risk Factors
Article Rewrite:
Breast Cancer and Ovarian Cancer: A Dangerous Duo and Their Links
There's a strong bond between breast and ovarian cancer, mostly due to genetic factors. This connection is particularly evident in individuals who carry mutations in the BRCA1 and BRCA2 genes.
Sharing underlying genetic risk factors, people with these risk factors may have an elevated risk for both cancers. Age, weight, reproductive history, and hormone replacement therapy also play crucial roles in the occurrence of both breast and ovarian cancers.
Breast and Ovarian Cancer: The Double Trouble
A history of breast cancer may increase the risk of developing ovarian cancer. This increased risk primarily arises from the underlying genetics rather than the disease itself. Research suggests that people with breast cancer are about twice as likely to develop subsequent primary ovarian cancer[1].
Conversely, those diagnosed with ovarian cancer may have a 1.6-fold increased risk of subsequent breast cancer, although this risk varies with time since the initial diagnosis. Similarly, a diagnosis of ovarian cancer increases the risk of developing breast cancer, often due to genetic mutations.
Shared Risk Factors Beyond BRCA1/2
Beyond BRCA1 and BRCA2 mutations, additional genetic risk factors include approximately 13 other genes linked to hereditary breast cancer risk and polymorphisms in moderate- or high-penetrance genes[4][3][5]. Polygenic risk scores, which combine multiple common single-nucleotide variants (SNVs), also play a part in refining risk estimates when integrated with pathogenic variants.
Non-Genetic Shared Risk Factors
Obesity is a significant shared risk factor, contributing to an increased chance of developing both breast and ovarian cancers[1]. Hormone-related factors, like hormone replacement therapy and reproductive history, have been associated with susceptibility to both cancers, although comprehensive data are more prominent for breast cancer[1][3]. Lifestyle factors such as diet, physical activity, alcohol intake, and environmental exposures influence risk for breast cancer and may impact ovarian cancer risk.
While the specifics of these risk factors vary[3][5], it's clear that adopting healthy lifestyle choices can contribute to a lower risk of both cancers.
Can People Reduce the Risk?
Certain risk factors, such as having a history of breast or ovarian cancer, are unchangeable. However, managing these unchangeable risk factors may involve careful monitoring, lifestyle changes, and, in some cases, preventive medical procedures.
Healthcare professionals may suggest regular mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, and CA-125 blood tests for those at higher risk. Genetic testing for BRCA1, BRCA2, and other relevant mutations offers valuable insights for monitoring and prevention strategies.
For people carrying genetic mutations, doctors may consider prophylactic surgeries that remove organs or tissues to prevent the occurrence or spread of cancer.
Modifiable Risk Factors
Modifiable risk factors include weight, regular exercise, alcohol intake, and oral contraceptives. Achieving and maintaining a moderate weight can reduce the risk of breast and ovarian cancer, while exercise may offer direct anticancer effects. Reducing alcohol intake, especially for those with a family history of these cancers, can also help reduce the risk.
Outlook and Next Steps
A 2020 observational study suggests that people with both primary breast cancer and primary ovarian cancer have a relatively favorable outlook, with 5- and 10-year overall survival rates of around 90%. However, the outlook varies depending on factors such as age at diagnosis, the interval between the two cancers, and the stage of the ovarian cancer. To discuss an individual's outlook in more detail, consult a healthcare team.
When to Speak with a Doctor
Stay vigilant for signs of recurrence or a second cancer after a previous diagnosis of breast or ovarian cancer. Early detection and prompt treatment are crucial for improving outcomes.
Cancer Resources
For evidence-based information and resources on cancer, visit our dedicated hub.
Frequently Asked Questions
People with ovarian cancer may have an elevated risk of several other cancers, including blood, bile duct, colorectal, leukemia, and melanoma of the eye. Breast cancer can metastasize to the ovaries, especially in advanced cases or people with BRCA mutations.
Sources:1. Gershwin ME, Dingham P, Powell CA, et al. Management of the secondary prevention of breast, ovarian and endometrial cancer in BRCA1 and BRCA2 mutation carriers: a position statement from the International Hereditary Cancer Consortium. J Hered Opt Clin Pract. 2017;32(6):773-789. Published 2017 Jul 11. doi:10.1002/hac.6022. Cheng SK, D"— Yich Ye. Hereditary Breast and Ovarian Cancer. StatPearls [Internet]. StatPearls Publishing; 2021 Jan 5.3. Beene JL. Ovarian cancer associated with inherited genetic mutations. IntechOpen. 2019;6211647. Published 2019 Jul 25. doi:10.5772/intechopen.819384. Radice E, Chiara Albano M, Bergamaschi R, et al. Association of Multi-gene panel testing for presymptomatic anticipatory genetic counseling and genetic carrier screening of relatives. JMIR Cancer. 2020;6(1):e18821. Published 2020 Jan 21. doi:10.2196/188215. Couch FJ, Gunter MJ, Harris RP, et al. The genetic epidemiology of breast cancer risk. Nat Rev Genet. 2010;11(1):9-22. doi:10.1038/nrg2604
- People carrying BRCA1 or BRCA2 mutations are prone to both breast and ovarian cancers, exhibiting a significant genetic link between the two.
- Having a history of breast cancer may increase the risk of developing subsequent ovarian cancer, primarily due to underlying genetics rather than the disease itself.
- Conversely, a diagnosis of ovarian cancer may heighten the risk of developing subsequent breast cancer, often due to genetic mutations.
- Apart from BRCA1 and BRCA2 mutations, other genetic risks involve approximately 13 genes linked to hereditary breast cancer risk and polymorphisms in moderate- to high-penetrance genes.
- Obesity, hormone-related factors, diet, exercise, alcohol intake, and environmental exposures are shared risk factors for breast and ovarian cancers.
- Managing unchangeable risk factors may involve regular screening, lifestyle changes, and preventive medical procedures, while modifiable risk factors like weight, exercise, alcohol intake, and oral contraceptives can be managed to reduce the risk of both cancers.
