Connection between Breast and Ovarian Cancer: Causes and Risk Factors
Breast and Ovarian Cancer: The Genetic Connection
There's a strong link between breast cancer and ovarian cancer, with genetic factors playing a significant role in this connection. People who carry mutations in the BRCA1 and BRCA2 genes are at a higher risk of developing both cancers.
Shared genetic risk factors between the two cancers, along with other factors, might increase the chances of both cancers.
Do Breast and Ovarian Cancers Affect Each Other?
If you've had breast cancer, you may face an increased risk of developing ovarian cancer. This risk is more pronounced if your breast cancer shows indications of genetic mutations like BRCA1 or BRCA2. However, this heightened risk is primarily due to genetic factors rather than the disease itself.
Research indicates that individuals with breast cancer are approximately twice as likely to develop subsequent primary ovarian cancer. People with ovarian cancer may also have a 1.6-fold increased risk of subsequent breast cancer, although the risk changes with the time since their initial cancer diagnosis. People with ovarian cancer may have a higher risk of breast cancer due to genetic mutations.
Other Risk Factors for Breast and Ovarian Cancers
BRCA1 and BRCA2 gene mutations are the most influential shared risk factors, with approximately 1 in 4 families with ovarian and breast cancer carrying BRCA1 gene mutations and approximately 1 in 5 families having BRCA2 mutations.
Other shared risk factors for breast and ovarian cancers may include:- a family history of either cancer- older age, with ovarian cancer occurring primarily in people over 40 years and breast cancer in those over 55 years- overweight or obesity- having a first child late (over 30 years)- never having children- not breastfeeding- hormone therapy after menopause
Can the Risk of Breast and Ovarian Cancers be Reduced?
Some risk factors, such as having a history of breast or ovarian cancer, are beyond our control. Managing these unchangeable risks involves careful monitoring, lifestyle modifications, and, in some cases, preventive medical procedures.
If you have a history of either breast or ovarian cancer and are genetically predisposed, healthcare professionals might recommend frequent and thorough screenings to detect new cancers early. These screenings may include:- regular mammograms- breast MRI scans- pelvic exams- transvaginal ultrasounds- CA-125 blood tests
Genetic testing for BRCA1, BRCA2, and other relevant mutations can be crucial for monitoring and prevention. For those with genetic mutations, doctors may suggest additional options such as prophylactic surgeries to remove organs or tissues to prevent the occurrence or spread of cancer.
Changeable Risk Factors
Some risks can be modified, such as:- Weight: Achieving and maintaining a moderate weight can help reduce the risk of both breast and ovarian cancer, as obesity may cause higher estrogen levels, potentially increasing breast cancer risk.- Regular Exercise: Regular physical activity has been linked to a lower risk of breast cancer, with limited evidence supporting a connection to ovarian cancer. Exercise can aid in maintaining a moderate weight and could also have direct anticancer effects.- Alcohol: Reducing alcohol intake can decrease the risk of breast cancer. Limiting alcohol consumption is advisable, as the risk increases with consumption levels, according to healthcare professionals.- Oral Contraceptives: Oral contraceptives may decrease the risk of ovarian cancer but may slightly increase the risk of breast cancer. It's essential to discuss contraception options with a doctor to weigh the risks based on your unique circumstances.
Outlook
A 2020 observational study suggests that people with both primary breast cancer and primary ovarian cancer generally have a relatively favorable outlook, with 5- and 10-year overall survival rates of around 90%. The outlook is typically more optimistic when the interval between the two cancers is longer. However, ovarian cancer following breast cancer often involves the diagnosis at a later stage, which can impact survival.
Various factors can affect an individual's outlook. If you want more information about your specific outlook, speak with your healthcare team.
When to Speak with a Doctor
If you notice signs or symptoms of breast or ovarian cancer, especially with a family history of these diseases, speak with a doctor, particularly if you have experienced a previous diagnosis of these cancers. Being vigilant for signs of recurrence or a second cancer after a previous diagnosis is crucial, as early detection and prompt treatment are vital for improved outcomes.
Cancer Resources
For more evidence-based information and resources on cancer, visit our dedicated hub.
Frequently Asked Questions
- Individuals with ovarian cancer may have an increased risk of the following cancers:
- breast cancer
- bladder cancer
- bile duct cancer
- colorectal cancer
- acute leukemia
- melanoma of the eye
- Breast cancer can metastasize (spread) to the ovaries, although this is fairly uncommon, typically occurring in individuals with advanced breast cancer.
- People at high risk of ovarian cancer include those who have:
- BRCA1 or BRCA2 gene mutations
- a family history of ovarian, breast, or colorectal cancer
- Lynch syndrome
- endometriosis
- never been pregnant
- had a late first pregnancy
- age over 40 years
Summary
Breast and ovarian cancer are linked due to shared genetic mutations, primarily in the BRCA1 and BRCA2 genes. People carrying these mutations have a significantly higher risk of developing both cancers. A personal or family history of one cancer increases the risk of the other, emphasizing the importance of genetic testing, periodic screenings, and preventive measures for high-risk individuals. People who have experienced breast or ovarian cancer may work with their healthcare team to monitor signs of another cancer.
- Those with genetic mutations in the BRCA1 or BRCA2 genes may have an increased risk of developing both breast and ovarian cancers.
- A family history of either breast or ovarian cancer, older age, being overweight or obese, having a first child late, never having children, not breastfeeding, and hormone therapy after menopause are other shared risk factors for breast and ovarian cancers.
- BRCA1 and BRCA2 gene mutations are most influential in families with both ovarian and breast cancer, with approximately 1 in 4 and 1 in 5 families, respectively, carrying these mutations.
- To reduce the risk of breast and ovarian cancers, maintaining a moderate weight, regular exercise, reducing alcohol intake, and oral contraceptives may offer some protection.
- If you have a history of either breast or ovarian cancer and are genetically predisposed, healthcare professionals might recommend frequent and thorough screenings as a preventive measure.
- People with ovarian cancer may have an increased risk of developing other cancers, including breast cancer, bladder cancer, bile duct cancer, colorectal cancer, acute leukemia, and melanoma of the eye.
