Connections between Breast and Ovarian Cancer: Examining Their Shared Links and Risk Factors
Rewritten Article:
The nexus between breast cancer and ovarian cancer is solid, predominantly due to genetic links. The tie is particularly strong for folks harboring mutations in the BRCA1 and BRCA2 genes.
Both breast and ovarian cancer share some underlying genetic risk factors. People with these risk factors may have an increased risk for both cancers.
Risk factors that are common to both tumors include older age, being overweight, never carrying a full-term pregnancy, and having never given birth. These factors may be influenced by the individual's choices.
Do breast and ovarian cancer influence each other's risk?
According to research, people who have had breast cancer may face a higher risk of developing ovarian cancer. This increased risk is more pronounced if the breast cancer is linked to BRCA1 or BRCA2 mutations. However, the elevated risk is mainly driven by the underlying genetic factors, rather than the disease itself.
Studies suggest that people with breast cancer are approximately twice as likely to experience a subsequent primary ovarian cancer.
For those diagnosed with ovarian cancer, they may have a 1.6-fold increased risk of subsequent breast cancer. The risk evolves over time since the initial cancer diagnosis.
People with ovarian cancer also have an increased risk of developing breast cancer, which may be linked to genetic factors.
Other risk factors for breast and ovarian cancers
BRCA1 and BRCA2 gene mutations represent the most significant shared risk factors. Scientific evidence indicates that around 50-60% of families with ovarian and breast cancer have BRCA1 gene mutations, while approximately 20% have BRCA2 mutations.
Other shared risk factors for breast and ovarian cancer may include:
- A family history of either cancer
- Age, with ovarian cancer typically occurring in people over 40 years, and breast cancer in individuals over 55 years old
- Being overweight or obese
- Having a first child after age 30
- Never having children
- Not breastfeeding
- Hormone therapy after menopause
Can people reduce the risk of breast and ovarian cancers?
Certain risk factors, such as having a previous history of breast or ovarian cancer, cannot be altered. Managing these unchangeable risk factors may involve careful monitoring, lifestyle changes, and, in some cases, preventive medical procedures.
A history of breast cancer increases the risk of ovarian cancer and vice versa, often due to genetic mutations such as BRCA1 or BRCA2. This situation cannot be altered, but management is possible.
Medical professionals may suggest that people with a history of breast or ovarian cancer undergo more frequent and thorough screenings to detect new cancers early. This may include undergoing:
- routine mammograms
- breast MRI scans
- pelvic exams
- transvaginal ultrasounds
- CA-125 blood tests
Genetic testing for BRCA1, BRCA2, and other relevant mutations can provide the best strategies for monitoring and prevention.
For those carrying genetic mutations, healthcare providers might consider additional options such as prophylactic surgeries. These procedures aim to remove organs or tissues to prevent the onset or progression of cancer.
Modifiable risk factors
Some risk factors are changeable:
- Weight: Achieving and maintaining a moderate weight can lower the risk of breast and ovarian cancer. Obesity can cause higher estrogen levels, which can increase the risk of breast cancer.
- Regular exercise: Regular physical activity may reduce the risk of breast cancer, and limited evidence supports a link with ovarian cancer. Exercise can help maintain a moderate weight and also has direct anticancer effects.
- Alcohol: Reducing alcohol intake can lower the risk of breast cancer. The risk increases with the amount of alcohol consumed, so healthcare professionals may recommend limiting alcohol.
- Oral contraceptives: Oral contraceptives may decrease the risk of ovarian cancer. However, they may slightly increase the risk of breast cancer. People can discuss contraception options with their doctor to weigh the risks based on their circumstances.
Outlook
A 2020 observational study indicates that people diagnosed with both primary breast cancer and primary ovarian cancer have a relatively favorable prognosis, with 5- and 10-year overall survival rates of around 90%.
The outlook is generally more positive when the interval between the two diseases is longer. However, ovarian cancer following breast cancer is more likely to occur at a later stage, which can negatively impact survival.
A person's age at their first cancer diagnosis and the time between the two cancers are crucial predictors of survival.
Many factors can affect a person's outlook. If someone wants more information about their individual outlook, they can consult with their healthcare team.
When to consult a doctor
People should consult with a doctor if signs or symptoms of breast or ovarian cancer appear, especially if they have a personal or family history of these diseases.
It is essential to 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 vital for improving outcomes.
Cancer resources
Discover more evidence-based information and resources for cancer by visiting our dedicated hub.
Frequently asked questions
People 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, but it is relatively uncommon. When it does occur, it typically transpires in people with advanced breast cancer. This situation may be more likely in breast cancers that are hormone receptor-positive or in people with BRCA mutations.
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
There is a robust link between breast cancer and ovarian cancer, mainly due to shared genetic mutations, particularly in the BRCA1 and BRCA2 genes. People with these mutations have a significantly higher risk of developing both cancers.
Besides genetic factors, a personal or family history of either cancer can signal an increased risk for the other. Understanding these factors can help individuals take preventive measures and monitor their health closely, particularly if they have a family history or genetic predisposition.
People who have experienced breast or ovarian cancer can work with their healthcare team to remain attentive for signs of another cancer.
- People with BRCA1 or BRCA2 gene mutations, a family history of either breast or ovarian cancer, or a personal history of these cancers may have an increased risk for both.
- In addition to genetic factors, shared risk factors for breast and ovarian cancer may include older age, being overweight or obese, never having children, not breastfeeding, and hormone therapy after menopause.
- Achieving and maintaining a moderate weight can lower the risk of breast and ovarian cancer, as obesity can cause higher estrogen levels, increasing the risk of breast cancer.
- Regular physical activity may reduce the risk of breast cancer, and limited evidence suggests a link with ovarian cancer, helping to maintain a moderate weight and having direct anticancer effects.
- Reducing alcohol intake can lower the risk of breast cancer, with the risk increasing with the amount of alcohol consumed.
- Ovarian cancer may increase the risk of subsequent breast cancer, which may be linked to genetic factors and evolution over time since the initial cancer diagnosis.
- For people with a history of breast or ovarian cancer, medical professionals may suggest more frequent and thorough screenings, including routine mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, CA-125 blood tests, and genetic testing for BRCA1, BRCA2, and other relevant mutations.
- People diagnosed with both primary breast cancer and primary ovarian cancer have relatively favorable prognoses with 5- and 10-year overall survival rates of around 90%, although ovarian cancer following breast cancer is more likely to occur at a later stage, which can negatively impact survival.
