Breast cancer risk assessments include predetermined, established factors that cannot be controlled. A family history of breast cancer is one such risk factor that has demonstrated that a person has a greater chance of developing breast cancer. Certain gene mutations that cause deoxyribonucleic acid (DNA) changes are prevalent in these families. Within them, the diagnosis of certain relatives, such as a mother with breast cancer, indicates how high the risk is of getting breast cancer.
Breast cancers that affect members of the same family suggest that inherited gene mutations might be responsible for a strong family history of breast cancer. Changes to several genes — including BRCA, phosphatase and tensin homolog (PTEN) or protein 53 (p53) genes — can result in this disease. The most common gene defects that cause hereditary breast cancer are altered BRCA1 and BRCA2 genes, whose functions lie in their ability to prevent abnormal tumor growths. In the presence of faulty BRCA genes, the risk of developing breast cancer becomes higher. These cancer-inducing mutated genes can be passed from one generation to the next and might lead to breast cancer in several family members and a significant family history of breast cancer.
How close of a relation an affected relative is identifies whether a family history of breast cancer is considered significant. In families with several relatives who have breast cancer, a hereditary risk is realized if the affected family members are blood related and from the same side of the family. If women with a family history of breast cancer observe the incidence of breast cancer in one first-degree relative, such as a parent, sibling or child, their chances of getting breast cancer doubles. Women who have two first-degree relatives with breast cancer experience three times the risk. Breast cancer risk also increases if there is a family history of ovarian, uterine or colon cancer.
For women who have a strong family history of breast cancer, genetic testing can be performed to determine whether they carry the faulty BRCA1 and BRCA2 genes. Specific family history patterns increase the likelihood of having abnormal BRCA genes. Genetic counseling is advised beforehand to determine the appropriateness of testing based on personal and family history and to discuss the expectations and risks involved in genetic testing.
Hereditary causes account for about 5-10 percent of breast cancer incidents. Women whose affected relatives carry mutated BRCA1 and BRCA2 genes or who have inherited these DNA changes from their parents experience a more elevated risk of developing breast cancer — up to 80 percent higher. Although a family history of breast cancer might signify an increased breast cancer risk, most breast cancer cases occur in women who have no such history.