Connection Between Breast and Ovarian Cancer: Identifying Factors That Increase Risk
A strong genetic link has been established between breast cancer and ovarian cancer. This connection is primarily due to shared mutations in the BRCA1 and BRCA2 genes.
Both forms of cancer share some underlying genetic risks. Those who carry these risk factors may have an elevated risk of developing either breast or ovarian cancer. Other shared risk factors include older age, overweight or obesity, and never carrying a pregnancy to term. Some of these risk factors can be influenced, such as achieving and maintaining a moderate weight.
People with a history of breast cancer may have an increased risk of developing ovarian cancer, particularly if the breast cancer is linked to genetic mutations in BRCA1 or BRCA2. However, this increased risk is mainly due to the inherent genetic factors rather than the disease itself. Research suggests that individuals with breast cancer are about twice as likely to develop subsequent primary ovarian cancer.
Conversely, individuals with ovarian cancer may have a 1.6-fold increased risk of subsequent breast cancer, although the risk varies with time since their initial diagnosis. Hazards of genetic mutations may also contribute to this risk.
Other shared risk factors for breast and ovarian cancers may include:
- A family history of either cancer
- Older age, with ovarian cancer typically occurring in people over 40 years, and breast cancer in those 55 years or older
- Overweight or obesity
- Having a first child over 30 years of age
- Never having children
- Not breastfeeding
- Hormone therapy after menopause
Mutations in the BRCA1 and BRCA2 genes are the most significant shared risk factors. Research suggests that around 65% of families with both ovarian and breast cancer have BRCA1 gene mutations, while approximately 20% have BRCA2 mutations.
Both breast cancer survivors and those with ovarian cancer can take steps to reduce the risk of a subsequent cancer. For some unchangeable risk factors, management methods such as regular screenings, lifestyle changes, and, in certain cases, preventive medical procedures can be implemented.
A history of either breast or ovarian cancer increases the risk of developing the other, especially if they share genetic mutations. Although this risk factor cannot be altered, it can be managed. Healthcare professionals may suggest more frequent and comprehensive screenings for people with a history of breast or ovarian cancer to catch any new cancers early. Such screenings may include regular mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, and CA-125 blood tests. Genetic testing for BRCA1, BRCA2, and other relevant mutations serves as the best strategy for monitoring and prevention.
In cases where individuals carry genetic mutations, doctors may consider additional options such as prophylactic surgeries. These procedures involve removing organs or tissues to prevent the occurrence or spread of cancer.
Modifiable risk factors include:
- Maintaining a moderate weight
- Regular exercise
- Limiting alcohol intake
- Discussing contraception options with a doctor
A 2020 observational study suggests that people with both primary breast cancer and primary ovarian cancer have a relatively favorable outlook, with 5-year and 10-year overall survival rates of around 90%. The outlook is generally more positive when the interval between the two diseases is longer. Early detection and prompt treatment are crucial for improving outcomes.
Individuals should speak with a doctor if signs or symptoms of breast or ovarian cancer appear, especially with a personal or family history of these diseases. After a previous diagnosis of breast or ovarian cancer, it is essential to remain vigilant for signs of recurrence or another cancer.
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People with ovarian cancer may also be at increased risk of bladder cancer, bile duct cancer, colorectal cancer, acute leukemia, and melanoma of the eye. Breast cancer can metastasize (spread) to the ovaries, although it is relatively uncommon.
Individuals at high risk of 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
- Had a late first pregnancy
- Age over 40 years
In conclusion, a history of breast cancer increases the risk of ovarian cancer, particularly if the breast cancer involves genetic mutations in BRCA1 or BRCA2. Regular screenings, lifestyle changes, and, in some cases, preventive medical procedures can help manage the risk. Those who have had either breast or ovarian cancer should take steps to monitor signs of another cancer.
- Those who carry BRCA1 or BRCA2 gene mutations may have an elevated risk of developing either breast or ovarian cancer.
- Individuals with a family history of breast, ovarian, or colorectal cancer may also be at increased risk of ovarian cancer.
- Research indicates that around 65% of families with both ovarian and breast cancer have BRCA1 gene mutations, while approximately 20% have BRCA2 mutations.
- Regular mammograms, breast MRI scans, pelvic exams, transvaginal ultrasounds, and CA-125 blood tests can be useful for early detection of secondary cancers in breast and ovarian cancer survivors.
- Modifiable risk factors for breast and ovarian cancers include maintaining a moderate weight, regular exercise, limiting alcohol intake, and discussing contraception options with a doctor.
- People with ovarian cancer may also be at increased risk of other medical conditions such as bladder cancer, bile duct cancer, colorectal cancer, acute leukemia, and melanoma of the eye.
