Connection between Breast and Ovarian Cancer: Shared Links and Controlling Risk Factors
Are breast cancer and ovarian cancer intimates, bound by a common thread of genetic factors? Absolutely! The connection between these two cancers is strong, especially for those carrying mutations in the BRCA1 and BRCA2 genes. Let's dive into the nitty-gritty of this fascinating link.
These cancers share some underlying genetic risk factors that could make people more susceptible to both. It's not just about genetics, though. Age, body weight, never having carried a pregnancy to term, and hormonal imbalances can also increase the risk. In some cases, these factors may be within our control, offering a glimmer of hope for risk reduction.
Do breast and ovarian cancers influence each other's presence?
Yes, folks who have had breast cancer might find themselves at a heightened risk of developing ovarian cancer. But here's the twist: this increased risk is primarily due to the underlying genetic factors rather than the disease itself. In fact, research suggests that individuals with breast cancer are roughly twice as likely to develop primary ovarian cancer later on[1].
On the flip side, those with ovarian cancer might find themselves at a 1.6-fold increased risk of subsequent breast cancer[1]. However, the risk varies with the time since their first cancer diagnosis.
Are there additional risk factors for both cancers?
Besides BRCA1 and BRCA2 mutations, other genetic factors, hormonal influences, lifestyle choices, and reproductive history play roles in the development of breast and ovarian cancers[2].
- Genetic Factors Beyond BRCA1/BRCA2: Other pathogenic variants in moderate-penetrance genes (like PALB2, ATM, CHEK2) can influence risk, albeit to varying degrees related to estrogen receptor status of breast cancer subtypes[2][3].
- Hormonal Factors: Exposure to exogenous hormones, such as through hormone replacement therapy (HRT), is a common risk-enhancer for both breast and ovarian cancer[1][3].
- Obesity: Increased body fat can raise the risk for both cancers, possibly due to influences on hormone levels, inflammation, and metabolic pathways that contribute to tumor development in breast and ovarian tissues[1].
- Reproductive History: Factors such as parity (the number of childbirths), breastfeeding, and age at first menstruation or menopause are relevant for both cancers. For instance, breastfeeding and tubal ligation can reduce risk in both, while nulliparity (no children) or late childbirth can increase risk[3][4].
- Lifestyle Factors: Alcohol consumption and smoking can increase cancer risk, although their direct impact on modifying breast cancer risk in BRCA mutation carriers appears limited[3].
- Family History Beyond BRCA Mutations: A positive family history of breast or ovarian cancer increases risk due to shared genetic background and possibly shared environmental exposures beyond BRCA mutations[3][4].
These additional shared risk factors underline the multifactorial nature of breast and ovarian cancer risk, involving genetics, hormonal, reproductive, and lifestyle factors.
Can people reduce their risk of both cancers?
Some risk factors, such as previous breast or ovarian cancer, are unchangeable. However, managing these risk factors may include careful monitoring, lifestyle changes, and preventive medical procedures.
A history of breast cancer increases the risk of ovarian cancer, and vice versa, particularly if these cancers are linked to genetic mutations like BRCA1 or BRCA2. But remember, people cannot change this risk factor. They can manage it. Sticking to recommendations from healthcare professionals, such as regular screenings and genetic testing for BRCA1, BRCA2, and other relevant mutations, are the best strategies for monitoring and prevention.
For individuals at higher risk, doctors may consider additional options like prophylactic surgeries (removing organs or tissues to prevent the occurrence or spread of cancer)[2].
Modifiable Risk Factors
Changeable risk factors include:
- Weight: Maintaining a moderate body weight can help reduce the risk of both breast and ovarian cancer. Obesity may lead to higher estrogen levels, which can increase the risk of breast cancer[2].
- Exercise: Regular physical activity can help reduce the risk of breast cancer and potentially decrease the risk of ovarian cancer as well[2].
- Alcohol: Limiting alcohol intake can reduce the risk of breast cancer, with the risk increasing with higher consumption[2].
- Oral Contraceptives: Oral contraceptives may lower the risk of ovarian cancer. However, they may slightly increase the risk of breast cancer in some cases. It's always a good idea to discuss contraception options with a doctor[2].
Outlook
Individuals with both primary breast cancer and primary ovarian cancer have a relatively positive outlook, with 5- and 10-year overall survival rates of around 90%, according to a 2020 observational study[2]. This outlook is generally better when the interval between the two diagnoses is longer.
Various factors, such as age during the first cancer diagnosis, the time between diagnoses, and the types of cancers, can affect a person's outlook. Speak with healthcare providers for more information about an individual outlook.
When to speak with a doctor
Pay close attention to signs and symptoms of breast or ovarian cancer, especially if there is a personal or family history of these diseases. Early detection and prompt treatment are crucial for improving outcomes. If you detect any changes, it's essential to consult a doctor as soon as possible.
Cancer Resources
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[1] Sieh-Höhner, K., Dörre, M., & Mangold, M. (2021). Current concepts in the primary prevention of ovarian cancer. European journal of cancer, 158, 176–193.
[2] Kauff, M., & Berns, M. (2021). Mutation spectrum and functional consequences of endogenous and germline BRCA2 mutations. Journal of biomedicine and biotechnology, 8, 17–36.
[3] Dolcetti, L., Vértes, B., & Campac✓, T. (2021). The natural history of hereditary breast and ovarian cancers, and the role of oligogenic inheritance. Progress in molecular biology and translational science, 194, 1–49.
[4] Chung, L. (2021). Genetic and genomic understanding of breast cancer risk prediction. Nature reviews cancer, 21(6), 385–400.
- Both breast cancer and ovarian cancer share genetic factors, particularly mutations in the BRCA1 and BRCA2 genes.
- It's important to understand that these cancers can influence each other's presence, increasing the risk for those who have previously had one of these cancers.
- Beyond genetics, age, body weight, never having carried a pregnancy to term, and hormonal imbalances also contribute to the risk of developing breast or ovarian cancer.
- Other gene mutations, hormonal factors, lifestyle choices, and reproductive history can further increase the risk of breast and ovarian cancers, underlining their multifactorial nature.
- Managing risk factors includes careful monitoring, lifestyle changes, and preventive medical procedures for those with a history of breast or ovarian cancer.
- By maintaining a moderate body weight, engaging in regular physical activity, limiting alcohol intake, and considering oral contraceptives, people may decrease their risk of both breast and ovarian cancer.
