Connection between Breast and Ovarian Cancer: Identified Factors and Associations
Living with a Higher Risk: Breast and Ovarian Cancer Connections
Breast cancer and ovarian cancer often share common ground, primarily due to genetic factors. It's the BRCA1 and BRCA2 gene mutations that create a strong connection between the two cancers.
These harmful mutations are detected in a significant percentage of families with both breast and ovarian cancer cases. Approximately 25% of families with breast cancer contributing to an ovarian cancer lineage have mutations in the BRCA1 gene, while around 20% carry mutations in the BRCA2 gene[1].
These genetic risk factors aren't the only commonalities between the two cancers. Factors such as age, obesity, reproductive history, and hormonal influences can also play a role in increasing the risk of both breast and ovarian cancers.
Does Having One Increase the Risk of the Other?
The link between breast cancer and ovarian cancer is two-way. If you've had breast cancer, it may increase your risk of developing ovarian cancer. The increased risk is particularly significant if your breast cancer has ties to genetic mutations, such as BRCA1 or BRCA2[2].
Research indicates that individuals with breast cancer are roughly twice as likely to develop secondary primary ovarian cancer[2]. Those with ovarian cancer may also have a 1.6-fold increased risk of subsequent breast cancer, although the specific risk varies depending on the time since their initial diagnosis[2][5].
Other Shared Risk Factors
Apart from genetic mutations, several other factors can increase the risk of both breast and ovarian cancers. These include:
- A family history of either cancer[1][5]
- Age - Ovarian cancer usually occurs in people over 40 years, while breast cancer is more common in those 55 years or older[3]
- Overweight or obesity[3]
- First birth over 30 years
- Never having children[4]
- Not breastfeeding[4]
- Hormone therapy after menopause[4]
Controllable Risk Factors
While some risk factors, such as a previous history of cancer, can't be changed, there are other factors that can be managed. These include:
- Weight: Achieving and maintaining a moderate weight can help reduce the risk of breast and ovarian cancer. Excess weight may cause higher estrogen levels, which can increase the risk of breast cancer[3]
- Regular exercise: Physical activity can help reduce the risk of breast cancer, with limited evidence also supporting a link to ovarian cancer reduction. Exercise can aid in maintaining a moderate weight and may have direct anticancer effects[3]
- Alcohol: Reducing alcohol intake can lower the risk of breast cancer. The risk increases with the amount consumed, so healthcare professionals may recommend limiting intake[3]
- Oral contraceptives: There is evidence suggesting that oral contraceptives may decrease the risk of ovarian cancer, although they might slightly increase the risk of breast cancer[4]
Outlook
A 2020 study observed that people diagnosed with both primary breast cancer and primary ovarian cancer had relatively favorable 5- and 10-year overall survival rates of around 90%[6]. The prognosis tends to be more positive when the interval between the two cancers is lengthier. However, ovarian cancer appearing after breast cancer is often diagnosed at a later stage, affecting the survival[6].
When to Consult a Doctor
Consult a healthcare professional if signs or symptoms of breast or ovarian cancer manifest, especially given a personal or family history of these diseases. Remain vigilant for indications of recurrence or a second cancer after a past diagnosis of either breast or ovarian cancer. Early detection and prompt treatment are vital for effective outcomes[7].
Cancer Resources
Explore more evidence-based information, cancer-related resources, and insights by visiting our dedicated hub.
Frequently Asked Questions
Other Cancers a Person with Ovarian Cancer May Develop:
- Bladder cancer
- Bile duct cancer
- Colorectal cancer
- Acute leukemia
- Melanoma of the eye
Cancers that Can Metastasize to the Ovaries:
Breast cancer can metastasize to the ovaries, although it is a relatively uncommon occurrence[1][6]. Such manifestations are more likely in advanced breast cancer cases, particularly those that are hormone receptor-positive or in individuals with BRCA mutations.
High-Risk Individuals for Ovarian Cancer Include:
- Those with BRCA1 or BRCA2 gene mutations
- A family history of ovarian, breast, or colorectal cancer
- Lynch syndrome
- Endometriosis
- Never been pregnant
- Late first pregnancy
- Age over 40 years [1][5]
Summary
Genetic mutations, particularly in the BRCA1 and BRCA2 genes, form a strong link between breast cancer and ovarian cancer. Other shared risk factors include demographic aspects, reproductive history, lifestyle choices, and other genetic factors. By understanding and managing these risk factors, individuals can take proactive steps in mitigating their breast and ovarian cancer risk.
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6580888/[2] https://www.breastcancer.org/symptoms/calendar/ovarian_cancer_risks[3] https://www.cancer.org/cancer/breast-cancer/causes-risks-prevention/risk-factors.html[4] https://www.cancer.org/cancer/ovarian-cancer/causes-risks-prevention/risk-factors.html[5] https://ghr.nlm.nih.gov/condition/ovarian-cancer[6] https://oncologypro.esmo.org/view-article/covid-19-cover-accounting-for-gender-impacts-on-survival-outcome-disparities-in-cancer-during-a-pandemic/2498570[7] https://www.cancer.org/treatment/survivorship-daily-life/research-progress/patient-and-caregiver-oriented-research-in-survivorship-progress-review.html[8] https://www.hopkinsmedicine.org/uabccr/breast_cancer_clinical_trials/.[9] https://clinicaltrials.gov/[10] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC679673/ (for prevention strategies)
- Breast cancer and ovarian cancer share a strong connection due to genetic factors, particularly BRCA1 and BRCA2 gene mutations.
- Families with both breast and ovarian cancer cases often have mutations in the BRCA1 (about 25%) or BRCA2 (around 20%) genes.
- A family history of either breast or ovarian cancer, age, obesity, reproductive history, and hormonal influences can increase the risk of both breast and ovarian cancers.
- Having breast cancer might increase the risk of developing ovarian cancer, especially if the breast cancer is linked to genetic mutations.
- The risk of subsequent breast cancer in individuals with ovarian cancer varies and is influenced by the time since their initial diagnosis.
- Maintaining a moderate weight, regular exercise, reducing alcohol intake, and managing hormone therapy can help reduce the risk of both breast and ovarian cancers; oral contraceptives may decrease the risk of ovarian cancer but might slightly increase the risk of breast cancer.
