Genetic Aspects of Breast Cancer: Connections, Varieties, Examinations, and Beyond
Breast cancer, like many diseases, can be influenced by genetic factors. The cost of genetic testing for these factors can range from less than $100 to $2,000, with insurance often covering these services [1].
Several genes have been identified as common contributors to an increased risk of developing breast cancer. Among these, BRCA1 and BRCA2 are the most well-known and prevalent genes associated with hereditary breast and ovarian cancer (HBOC) syndrome [1][3][5].
Individuals carrying mutations in the BRCA1 or BRCA2 genes have a significantly increased risk of breast cancer. These genes are tumor suppressor genes responsible for repairing DNA damage. When these genes are defective, cells divide uncontrollably, leading to tumor formation [1][2].
The associated lifetime risks for carriers of these mutations vary:
- Women with BRCA1 or BRCA2 mutations have a substantially increased lifetime breast cancer risk compared to the general population (often cited as around 45-70%, though exact numbers can vary in studies) [1][3].
- PALB2 mutation carriers have about a 30 to 40% lifetime risk of developing breast cancer due to its role interacting with BRCA1/BRCA2 genes [1].
- Mutations in TP53, associated with Li-Fraumeni syndrome, carry a very high risk of multiple cancers, including breast cancer, with TP53 considered one of the most penetrant tumor suppressor genes [2][3].
- Men with BRCA1 mutations have a 1 to 5% lifetime risk for male breast cancer, while BRCA2 mutations also elevate male breast cancer risk [4].
- Other high-penetrance genes like PTEN, CDH1, STK11, CHEK2, and ATM contribute to breast cancer risk to varying, typically lower degrees than BRCA genes but are still important in familial breast cancer cases [1][5].
Other factors that can increase a person's risk of developing breast cancer include getting older, dense tissue, and previous benign breast conditions [1]. People with a change in the NF1 gene are likely to develop breast cancer at some point in their lives [1]. The CHEK2 gene, similar to BRCA genes, helps repair DNA, and its changes increase the likelihood of developing breast cancer [1].
Online genetic testing kits are not as accurate as clinical genetic tests [1]. It is recommended to organize genetic testing through a genetic counselor and a blood test [1].
Research suggests that certain genetic variants may make women of African descent more susceptible to aggressive tumors due to lower immune responses and higher inflammation [1]. Black women tend to develop breast cancer at a younger age and more frequently in aggressive forms like triple-negative breast cancer [1].
BRCA genes have also been linked to the development of ovarian and pancreatic cancer [1]. Changes in the PALB2 gene may also increase the risk of ovarian cancer [1]. A father can pass the BRCA gene to his daughter, and mutations in the BRCA genes can increase the risk of developing breast cancer [1].
A 2023 study found that BRCA and PALB2 genes contribute to breast cancer in Black African women, but sample sizes are smaller compared to studies involving white women [1].
Adopting healthy lifestyle choices, such as avoiding alcohol, aiming for 300 minutes of physical activity per week, eating a healthy diet, not smoking, taking medications to reduce cancer risk, and undergoing prophylactic surgery, can help reduce the risk of breast cancer [1].
Inheriting just one faulty copy of the ATM gene increases the risk of developing breast cancer [1]. Changes in the PTEN gene increase the risk of Cowden's syndrome, a condition that causes benign and invasive breast tumors, as well as thyroid, ovary, and digestive tract growths [1]. A change in the NBN gene makes it unable to repair DNA, causing cells to continuously divide, which can lead to breast cancer [1]. Changes in the STK11 gene have been linked to many types of cancer, including breast cancer, and people who inherit a faulty version of this gene may also notice pigmented spots in their mouths and on their lips [1].
It is crucial to remember that only identical twins can have exactly the same genes. Two sisters who are not identical twins may inherit different genes from either parent [1].
In conclusion, understanding the genetic factors linked to breast cancer risk can help individuals make informed decisions about their health. Genetic testing, combined with a healthy lifestyle, can provide valuable insights and potentially reduce the risk of developing breast cancer.
- Breast cancer, similar to many diseases, can be influenced by genetic factors, and the cost of genetic testing for these factors can range from less than $100 to $2,000, with insurance often covering these services.
- Several genes, such as BRCA1 and BRCA2, have been identified as common contributors to an increased risk of developing breast cancer, with BRCA1 and BRCA2 being the most well-known and prevalent genes associated with hereditary breast and ovarian cancer (HBOC) syndrome.
- Individuals carrying mutations in the BRCA1 or BRCA2 genes have a significantly increased risk of breast cancer, as these genes are tumor suppressor genes responsible for repairing DNA damage.
- Women with BRCA1 or BRCA2 mutations have a substantially increased lifetime breast cancer risk compared to the general population, often cited as around 45-70%, though exact numbers can vary in studies.
- The CHEK2 gene, similar to BRCA genes, helps repair DNA, and its changes increase the likelihood of developing breast cancer.
- Adopting healthy lifestyle choices, such as avoiding alcohol, aiming for 300 minutes of physical activity per week, eating a healthy diet, not smoking, taking medications to reduce cancer risk, and undergoing prophylactic surgery, can help reduce the risk of breast cancer.
- It is crucial to remember that only identical twins can have exactly the same genes, as two sisters who are not identical twins may inherit different genes from either parent.
- Understanding the genetic factors linked to breast cancer risk can help individuals make informed decisions about their health, and genetic testing, combined with a healthy lifestyle, can provide valuable insights and potentially reduce the risk of developing breast cancer.
