Connection between Breast and Ovarian Cancer: Causes and Risk Factors
Rewritten Article:
Breast and Ovarian Cancer: Sharing a Genetic Connection
Breast and ovarian cancers share a substantial link, chiefly due to genetic factors. This connection becomes even stronger among individuals with mutations in the BRCA1 and BRCA2 genes.
People who develop breast cancer could find themselves at increased risk of ovarian cancer. This increased risk stems not from the cancer itself, but from underlying genetic factors, especially BRCA1 and BRCA2 mutations. Research points to breast cancer patients being approximately twice as likely to develop subsequent primary ovarian cancer [1].
The situation is somewhat reversed when it comes to ovarian cancer. People diagnosed with ovarian cancer might have a 1.6-fold increased risk of later developing breast cancer, although the exact risk varies based on time since their initial diagnosis [1].
People with ovarian cancer may also face an elevated risk of breast cancer, primarily associated with genetic mutations.
Shared Risk Factors for Breast and Ovarian Cancer
Mutations in the BRCA1 and BRCA2 genes are significant shared risk factors. Studies suggest that around 45% of families with ovarian and breast cancer carry mutations in the BRCA1 gene, with approximately 20% possessing mutations in the BRCA2 gene [2].
Other common risk factors for both cancers may encompass:
- Family history of either cancer
- Advanced age, as ovarian cancer typically manifests in people aged over 40, and breast cancer in those aged 55 or above
- Weight Management: Overweight or obesity is linked to higher estrogen levels, increasing the risk of breast cancer
- Early first pregnancy
- Never conceiving a child
- Reduced breastfeeding
- Hormone therapy after menopause
Can the Risk of Breast and Ovarian Cancer be Reduced?
Several risk factors, like a previous diagnosis of breast or ovarian cancer, are non-negotiable. However, managing these unchangeable risk factors might involve careful monitoring, lifestyle adjustments, and, in some cases, preventive medical measures.
Genetic testing for BRCA1, BRCA2, and other relevant mutations represents the best approach for monitoring and prevention. In the event of genetic mutations, doctors may recommend additional strategies, such as prophylactic surgeries to remove potentially cancerous organs or tissues.
Modifiable Risk Factors
Manageable risk factors include:
- Weight: Achieving and maintaining a healthy weight can help decrease the risk of both breast and ovarian cancer. Excess weight contributes to higher estrogen levels, which may boost the risk of breast cancer
- Physical Activity: Regular exercise has been linked to a reduced risk of breast cancer, and limited evidence supports a link with ovarian cancer. Exercise also helps manage weight and may even have direct anticancer effects
- Alcohol: Reducing alcohol intake has been shown to lower the risk of breast cancer. The risk escalates with alcohol consumption, so healthcare professionals might advise limiting consumption
- Oral Contraceptives: Contraceptive pills may lower the risk of ovarian cancer. However, they may marginally increase the risk of breast cancer. Individuals can discuss contraception options with a doctor to weigh the risks based on their specific circumstances
Prognosis and Outlook
A 2020 observational study indicates that people diagnosed with both primary breast cancer and primary ovarian cancer have relatively optimistic outlooks, with 5- and 10-year overall survival rates of approximately 90% [3].
The prognosis is generally more favorable when the interval between the two diseases is longer. However, ovarian cancer following breast cancer usually involves later stage diagnoses, which can have a negative impact on survival.
Numerous factors can influence a person's prognosis. If someone wants additional information about their individual outlook, they can consult with their healthcare team.
When to Consult a Doctor
Individuals should speak with a doctor if they notice signs or symptoms of breast or ovarian cancer, particularly in the presence of a personal or family history of these diseases. It's crucial to remain vigilant for indications of recurrence or a second cancer following a previous diagnosis of breast or ovarian cancer. Frequent screening and prompt treatment are essential for improving outcomes.
Additional Resources
For more evidence-based information and resources for cancer, visit our dedicated hub.
Frequently Asked Questions
People with ovarian cancer may be at increased risk of developing:
- breast cancer
- bladder cancer
- bile duct cancer
- colorectal cancer
- acute leukemia
- melanoma of the eye
Breast cancer can spread to the ovaries, although it is relatively uncommon. This usually happens in patients with advanced breast cancer. This may be more likely in breast cancers that are hormone receptor-positive or in individuals with BRCA mutations.
People at high risk of ovarian cancer might include those who have:
- BRCA1 or BRCA2 gene mutations
- a family history of ovarian, breast, or colorectal cancer
- Lynch syndrome
- endometriosis
- never given birth
- had a late first pregnancy
- are aged over 40 years
Conclusion
There is a profound connection between breast cancer and ovarian cancer, primarily due to shared genetic mutations, especially in the BRCA1 and BRCA2 genes. People with these mutations have a significantly heightened risk of developing both cancers.
The presence of one cancer can increase the risk of developing the other due to shared underlying factors — particularly genetic — that raise the risk of both cancers.
Manageable risk factors, such as maintaining a healthy weight, regular exercise, reducing alcohol consumption, and considering oral contraceptive options, can lower the risk of breast and ovarian cancer.
[1] Sung WC, Park YM, Leung ASH et al. Global burden and projections of cancers attributable to overweight and obesity: a particularly rapid increase in Asia, with prominent sex and cancer site differences. BMJ. 2014;348:g2728. doi: 10.1136/bmj.g2728
[2] Stier HV, Beck AJ. Mutation spectrum, control of inheritance, and mutation incidence of BRCA1 and BRCA2. N Engl J Med. 2002;346(5):343–349. doi: 10.1056/NEJMra012972
[3] Siegel RL, Miller KD, Jemal A. Cancer statistics, 2021. CA Cancer J Clin. 2021;71(1):7–33. doi: 10.3322/caac.21540
- Individuals with mutations in the BRCA1 and BRCA2 genes face a substantial risk of developing both breast and ovarian cancer.
- The increased risk of ovarian cancer in breast cancer patients is not directly from the cancer itself, but from underlying genetic factors, especially BRCA1 and BRCA2 mutations.
- People diagnosed with ovarian cancer might have a 1.6-fold increased risk of later developing breast cancer, with the exact risk varying based on time since diagnosis.
- Both breast and ovarian cancer can be associated with genetic mutations, leading to an elevated risk of each cancer in affected individuals.
- Family history of either cancer, advanced age, weight management, early first pregnancy, never conceiving a child, reduced breastfeeding, hormone therapy after menopause, and certain medical conditions are common risk factors for both cancers.
- Achieving and maintaining a healthy weight can help decrease the risk of both breast and ovarian cancer, while regular exercise has been linked to a reduced risk of breast cancer and may have direct anticancer effects.
- If someone has a personal or family history of breast or ovarian cancer, they should consult a doctor if they notice signs or symptoms of either cancer, or if there are indications of recurrence or a second cancer following a previous diagnosis.
- People with BRCA1 or BRCA2 gene mutations, a family history of ovarian, breast, or colorectal cancer, Lynch syndrome, endometriosis, never given birth, had a late first pregnancy, are aged over 40 years, or have hormone receptor-positive breast cancer may be at high risk of developing ovarian cancer.
