What Causes Breast Cancer?

How some factor cause cells cancer to become cancerous, it is not yet exactly known, hormones not fully-understood role in many cases of breast cancer.

“In breast cancer, some of the cells in your breast begin growing abnormally. These cells divide more rapidly than healthy cells do and may spread (metastasize) through your breast, to your lymph nodes or to other parts of your body. The most common type of breast cancer begins in the milk-producing ducts, but cancer may also begin in the lobules or in other breast tissue.”

Changes in DNA can cause normal breast cells to become cancerous. DNA is the chemical in each of our cells that makes up our genes the instructions for how our cells function.

Certain genes that speed up cell division are called oncogenes. Others that slow down cell division, or cause cells to die at the right time, are called tumor suppressor genes. Cancers can be caused by DNA mutations (changes) that "turn on" oncogenes or "turn off" tumor suppressor genes.

“ it isn't clear what causes normal breast cells to become cancerous. Doctors do know that only 5 percent to 10 percent of breast cancers are inherited. Families that do have genetic defects in one of two genes, breast cancer gene 1 (BRCA1) or breast cancer gene 2 (BRCA2), have a much greater risk of developing both breast and ovarian cancer. Other inherited mutations — including the ataxia-telangiectasia mutation gene, the cell-cycle checkpoint kinase 2 (CHEK-2) gene and the p53 tumor suppressor gene — also make it more likely that you'll develop breast cancer. If one of these genes is present in your family, you have a 50 percent chance of having the gene.”

Inherited gene mutations

Women have already begun to benefit from advances in understanding the genetic basis of breast cancer. Genetic testing can identify some women who have inherited mutations in the BRCA1 or BRCA2 tumor suppressor genes (or less commonly in other genes such as PTEN or p53). These women can then take steps to reduce their risk of developing breast cancers and to monitor changes in their breasts carefully to find cancer at an earlier, more treatable stage.

Most genetic mutations related to breast cancer aren't inherited. These acquired mutations may result from radiation exposure , women treated with chest radiation therapy for lymphoma in childhood or during adolescence when breasts are developing have a significantly higher incidence of breast cancer than do women not exposed to radiation. Mutations may also develop as a result of exposure to cancer causing chemicals, such as the polycyclic aromatic hydrocarbons found in tobacco and charred red meats.

So how relationship exists between a person's genetic makeup and environmental factors that may increase the risk of breast cancer.?? Researcher trying to discover about that relation.