All genes in the human body store information about the structure of proteins that are synthesized as a result of gene expression. The BRCA1 and BRCA2 genes code for proteins that are involved in repairing damage to the genetic material of cells. These are, for example, DNA breaks caused by radiation or exposure to mutagenic substances. The BRCA1 and BRCA2 gene products also control the course of the cell cycle and cell division, and are important during embryonic development.
It is estimated that one in 800 women carries a BRCA mutation, as does Angelina Jolie, whose mother had just died of breast cancer. The mutated gene ceases to fulfill its functions properly. As a result of the mutation, the gene loses its ability to repair broken genetic material, which can lead to the formation of abnormal proteins. Such a cell usually undergoes controlled death – apoptosis. Sometimes, however, as a result of an error in repairing DNA damage, the cell gains the ability to divide uncontrollably and become immortal, which is characteristic of malignant neoplasms. Women with the mutation are at high risk of developing not only breast cancer, but also ovarian cancer.
Genetic testing is especially recommended for all women with a family history of breast and ovarian cancer. They should also be performed between the ages of 20 and 30 if a mutation is detected in a family member or relatives. In addition to prophylactic purposes, the test can also be used for diagnosis in the case of atypical forms of breast cancer, for example, bilateral cancer in young women or breast cancer in men.
A mutation in the BRCA1 or BRCA2 gene significantly increases the risk of developing breast cancer in a woman’s life. The probability of developing a malignant tumor in a carrier of the mutation before the age of 70 is 50 to 90 percent, compared with an average risk of 13 percent. in the general population. Breast cancer associated with BRCA usually appears in younger women, on average 42-45 years old. The mutation may appear sporadically or run in families and lead to the development of hereditary neoplasms – it is 7-10 percent. all BRCA 1 or 2 induced tumors.
Breast cancer associated with the BRCA mutation is very easy to metastasize and is usually advanced at diagnosis. It also has a very specific histological picture – usually it is infiltrating ductal or undifferentiated carcinoma in which estrogen, progesterone and HER2 receptors are absent. For this reason, it is called triple negative cancer. The prognosis for hereditary breast cancer is comparable to that of sporadic neoplasms, despite the primary malignancy.
Women with BRCA1 and BRCA2 mutations have an increased risk of developing ovarian cancer – it is 45%. compared to 2 percent. general population. It is usually a less differentiated cancer, but with a better sensitivity to cisplatin treatment and a better prognosis than in the case of sporadic neoplasms. A mutation in the BRCA gene also increases the risk of developing tubal and peritoneal cancer, estimated at around 10 percent.
The most effective way to prevent the development of breast and ovarian cancer if mutations in the BRCA1 and BRCA2 genes are detected is complete mastectomy of both breasts at the age of 40-50 years and adnexectomy, i.e. removal of the appendages (ovaries and fallopian tubes) in women aged 35-40 years or after the birth of the planned children.
Removal of the ovaries alone reduces the risk of developing a malignant tumor by about 70-95%, and also lowers the risk of breast cancer by more than a half. Some reports suggest that having a child under the age of 25 has a protective effect on the development of breast cancer. Likewise, ligation of the fallopian tubes and use of hormonal contraception can reduce the risk of ovarian cancer in women. Nevertheless, the most effective known method of prophylaxis is the removal of appendages and breasts.
All over the world, October is Breast Cancer Awareness Month. We will systematically publish materials on the diagnosis, treatment and prevention of this cancer on our website.
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