Researchers have linked a number of genes, including BRCA1 and BRCA2, to the development of breast cancer. Although gene changes may increase some people’s risk of developing breast cancer, environment and lifestyle are also important factors.
Other genes that could increase the likelihood of a person developing breast cancer include ATM, TP53, CHEK2, and PTEN.
Read on to learn more about breast cancer-related genes and how they increase the risk of breast cancer.
BRCA1 and BRCA2 are tumor suppressor genes. If there is a fault in either of these genes, they no longer repair broken DNA. When this happens, cells divide uncontrollably and form tumors.
According to the American Cancer Society, if a woman inherits just one faulty copy of either of these genes, there is a 70% chance that they will develop cancer by the age of 80 years. They will also likely develop breast cancer at a younger age and have it in both breasts.
Researchers have also linked the BRCA genes to the development of ovarian cancer.
There are a number of genes that could increase a person’s risk of developing breast cancer.
These include the following.
A change in this gene results in a protein that interacts with the BRCA1 and BRCA2 genes. People with a faulty PALB2 gene have a 33–58% lifetime risk of developing breast cancer.
Researchers have also linked changes in this gene to an increase in the risk of ovarian cancer. However, more studies are necessary to confirm this.
Similar to the BRCA genes, CHEK2 helps repair DNA. If the gene changes, it increases the likelihood of developing breast cancer.
A change in this gene increases the risk of Cowden’s syndrome. This is a condition that causes benign and invasive breast tumors. It also causes thyroid, ovary, and digestive tract growths.
This gene helps repair DNA or kills the cell if it cannot repair the DNA. If a person inherits just one faulty copy of this gene, their risk of developing breast cancer increases.
Changes in this gene lead to Li-Fraumeni syndrome. Having this syndrome increases the risk of breast cancer, leukemia, brain tumors, and connective tissue cancer.
Researchers have linked changes in this gene to many types of cancer, including breast cancer.
People who inherit a faulty version of this gene may also notice pigmented spots in their mouths and on their lips.
A change in this gene causes hereditary gastric cancer and increases the risk of breast cancer.
When a change in this gene occurs, it is unable to repair DNA. This means that cells can continuously divide,
People with a change in the NF1 gene
The genetic mutations that increase the likelihood of breast cancer are the same for all women.
The researchers found that harmful mutations occurred in:
- 10.3% of those with estrogen receptor (ER)-negative breast cancer
- 5.2% of those with ER-positive breast cancer
- 2.3% of those without a breast cancer diagnosis
The researchers noted that changes in the RAD51D gene increased the risk of ER-negative cancer, while changes in CHEK2, ATM, ERCC3, and FANCC carry a moderate risk of ER-positive cancer.
If there is a fault in the RECQL gene, there is a moderate risk of all types of breast cancer.
If breast cancer runs in a person’s family, they may want to undergo genetic testing. Genetic testing can determine whether or not a person has breast cancer genes.
Before contacting a counselor or taking any genetic test, a person may want to consider how the results could affect them and their family.
A genetic counselor can organize a blood test to analyze the person’s DNA for gene changes that could increase their risk of breast cancer.
If the test reveals that the person has a high risk of developing breast cancer or any other condition, they can ask the genetic counselor for advice on what to do next.
This advice could include:
- lifestyle changes
- training in early symptom recognition
- preventive surgery
The cost of genetic testing can range from $300 to $5,000. If a person wants to contact a genetic counselor or get genetic testing, they should first check their insurance to see if it covers these services.
In addition to inheriting particular genes, some other breast cancer risk factors include:
- Getting older: Women over 55 years of age tend to develop breast cancer more than younger women.
- Height: Taller women tend to develop breast cancer more than shorter women. The reasons for this are unclear. However, it may be connected to nutrition in early life, genetics, and hormonal factors.
- Dense tissue: Women with lots of fatty and fibrous breast tissue have a higher risk of developing breast cancer.
- Previous benign breast conditions: Having benign conditions such as fat necrosis, fibrosis, adenosis, and others may increase a person’s risk of breast cancer.
Some protective factors could help reduce the risk of a person developing breast cancer, even if a faulty gene is present.
These factors include:
- avoiding alcohol
- aiming for 300 minutes of physical activity per week
- not having breast implants
- eating a healthy diet
- not smoking
- taking medications to prevent cancer
- undergoing protective surgery
Changes in some genes may increase the risk of a person developing breast cancer. If a person has a fault in the BRCA1 or BRCA2 gene, there is a 70% chance that they will develop breast cancer by the time they are 80 years old.
If breast cancer runs in a person’s family, they may want to consider contacting a genetic counselor, who could offer a genetic test. The test would screen their DNA to detect any genetic changes.
To reduce the risk of breast cancer, a person should try to eat a healthy diet and keep active. If someone has inherited a faulty gene, they may be able to take medications or undergo protective surgery to prevent the development of breast cancer.