Breast cancer is a serious and dangerous disease that will lead to the death of about one in 35 women. Breast tumors form when normal cells in breast tissue undergo cellular and genetic changes, causing these cells to grow uncontrollably. Despite the severity of this disease, little is known about the exact causes of breast cancer. However, a number of factors are known to influence the onset of breast cancer and could be of interest to women hoping to avoid this condition.
Gender
The number one risk factor for breast cancer is simply being female. The American Cancer Society explains that female sex hormones such as estrogen and progesterone can act as signals for breast cancer growth. While it is possible for men to get breast cancer, women are 100 times more likely to be diagnosed with a breast tumor than men.
Age
Age is also a contributing factor to breast cancer. According to the American Cancer Society, women over the age of 55 are more likely to develop breast cancer than younger women. This is in part due to hormonal changes that occur with menopause. Older women are also more likely to accumulate mutations in breast cancer genes that can lead to tumor onset.
Breast Cancer Genes
A number of genetic changes are known to cause or increase the likelihood of developing breast cancer. The National Cancer Institute describes how changes in the BRCA1 and BRCA2 genes are a primary cause of breast cancer. Mutations in these genes can cause DNA to become unstable and help to promote cancer progression and unregulated cell growth. Women who inherit mutated versions of the BRCA genes may have up to an 80 percent chance of developing breast cancer. Another gene commonly disrupted in breast cancer is the HER2 gene. This gene is often found to be multiplied in breast cancer, leading to "HER2-positive" breast cancer. HER2 acts to signal breast tumor growth. When HER2 levels become unregulated as a result of mutation, certain breast tumor cells can grow uncontrollably to form solid tumors.
Obesity
Body fat can also contribute to breast cancer formation. According to the Mayo Clinic and the American Cancer Society, body fat plays a role in estrogen production in women. When body fat levels rise, so do estrogen levels, and this will increase breast cancer risk. The effect of body fat on breast cancer formation is substantially increased in older women as estrogen levels become abnormal in postmenopausal, obese women. While body fat is known to have a role in breast cancer risk, diets high in fat are not known to contribute to breast cancer directly.
