Connection Between Breast and Ovarian Cancer: Causes and Risks
Breast and Ovarian Cancer: Genetic Linkages and Potential Risks
A robust connection exists between breast and ovarian cancer, primarily attributable to shared genetic factors. The relationship is notably strong for individuals carrying mutations in the BRCA1 and BRCA2 genes.
Curiously, both breast and ovarian cancers share some inherent genetic risk factors. People with these genetic predispositions may face an elevated risk for both types of cancer. Communal risk factors encompass aging, excess weight or obesity, and never carrying a pregnancy to term. Some of these risk factors can be managed, such as working towards a moderate weight.
According to research, those who have battled breast cancer may have a heightened risk of developing ovarian cancer. This is especially true if breast cancer is connected to BRCA1 or BRCA2 gene mutations. However, this augmented risk stems from underling genetic factors rather than the disease itself. Epidemiologic data indicates that individuals with breast cancer are roughly twice as likely to develop subsequent primary ovarian cancer.
Reciprocally, people with ovarian cancer may be at a 1.6-fold increased risk of subsequent breast cancer, though the risk fluctuates with time since the initial cancer diagnosis. People with a history of ovarian cancer may be at genetic risk of developing breast cancer as well.
Mutations in the BRCA1 and BRCA2 genes are the most significant shared risk factors. Studies suggest that around 65% of families with ovarian and breast cancer have BRCA1 gene mutations, while approximately 20% have BRCA2 mutations. Other common risk factors for both breast and ovarian cancer may comprise:
- familial history of either cancer
- advanced age, with the average age for ovarian cancer typically being over 40, and breast cancer appearing predominantly in individuals over 55 years old
- obesity or excess weight
- late motherhood
- infertility
- not breastfeeding
- hormone therapy after menopause
Can People Reduce the Risk of Breast and Ovarian Cancer?
Certain risk factors are unalterable, like a history of breast or ovarian cancer. In these instances, careful monitoring, lifestyle changes, and, on occasion, preventive medical procedures may be advised.
A history of breast cancer increases the risk of ovarian cancer and vice versa, particularly if these cancers are associated with genetic mutations such as BRCA1 or BRCA2. Since this risk factor can't be altered, people can manage it.
Healthcare professionals may suggest that people with a history of breast or ovarian cancer undergo more frequent and extensive screenings to catch any new cancers early. This might include undergoing regular mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, or CA-125 blood tests. Genetic testing for BRCA1, BRCA2, and other relevant mutations are the best strategies for monitoring and prevention. For those carrying genetic mutations, doctors may consider additional options such as prophylactic surgeries to remove organs or tissues and prevent the occurrence or spread of cancer.
Modifiable risk factors encompass:
- Weight: Achieving and maintaining a moderate weight can help reduce the risk of both breast and ovarian cancer. Obesity may stimulate higher estrogen levels, which can augment the risk of breast cancer.
- Regular Exercise: Regular physical activity can lower the risk of breast cancer, and limited evidence supports its link with reduced ovarian cancer risk as well. Exercise not only helps maintain a moderate weight but might also have direct anticancer effects.
- Alcohol Consumption: Moderating alcohol consumption can minimize the risk of breast cancer, and healthcare professionals may advise limiting intake for this reason.
- Oral Contraceptives: Oral contraceptives may help protect against ovarian cancer but may slightly increase the risk of breast cancer. People can consult with a healthcare provider about contraception options to balance the risks based on their personal circumstances.
Outlook
According to a 2020 observational study, people with both primary breast cancer and primary ovarian cancer have a relatively favorable prognosis, with 5- and 10-year overall survival rates of approximately 90%. The outlook is generally more encouraging when the interval between the two diseases is lengthy. However, ovarian cancer following breast cancer is more likely to be diagnosed at a later stage, which can negatively affect survival. A person's age during their first cancer diagnosis and the time between the two cancers serve as significant predictors of overall survival.
Various factors can impact a person's outlook. If someone seeks more information about their individual outlook, they can discuss it with their healthcare team.
When to Speak with a Doctor
People should consult a doctor if signs or symptoms of breast or ovarian cancer appear, especially with a personal or family history of these diseases. It's essential to remain 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
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Frequently Asked Questions
- Individuals with ovarian cancer may face 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 it is relatively uncommon. When it does occur, it usually arises in people with advanced breast cancer, particularly for hormone receptor-positive breast cancers or those with BRCA mutations.
- People at high risk of ovarian cancer may 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
- The shared genetic factors between ovarian and breast cancers are significant, particularly for individuals carrying mutations in the BRCA1 and BRCA2 genes.
- People with a history of breast cancer may have a heightened risk of developing ovarian cancer, and vice versa, especially if these cancers are associated with genetic mutations.
- Regular physical activity and achieving and maintaining a moderate weight can help reduce the risk of both breast and ovarian cancer.
- While a history of breast or ovarian cancer is unalterable, people can manage the risk by undergoing more frequent and extensive screenings, and in some cases, prophylactic surgeries may be considered.
- In addition to breast and ovarian cancer, individuals with ovarian cancer may face an increased risk of other cancers, such as bladder, bile duct, colorectal, acute leukemia, and melanoma of the eye.
- People at high risk of ovarian cancer may include those with BRCA1 or BRCA2 gene mutations, a family history of ovarian, breast, or colorectal cancer, Lynch syndrome, endometriosis, never being pregnant, having a late first pregnancy, or being over 40 years old.
