Any factor that increases the chance of developing the disease is called a risk factor. Risk factors for breast cancer include advanced age, early menarche, advanced first birth or never having had a child, history of breast cancer or a history of benign breast cancer, mother or sister with breast cancer, history of radiation therapy to the chest or breast, high-dose x-ray exposure to the breast, oral estrogen and alcohol abuse, and Caucasians are more likely to develop the disease than other races. Genes within cells are carriers of genetic information from parents. Familial or hereditary breast cancer accounts for 5-10% of all breast cancers, and genetic variations associated with breast cancer are more common in certain ethnic groups. Patients with breast cancer-associated gene changes have an increased risk of developing cancer in the opposite breast, as well as an increased risk of ovarian and other cancers. Men with altered breast cancer-related genes are also at increased risk of developing breast cancer. In families with a high incidence of breast cancer, the risk of cancer can be predicted by testing for mutations in certain genes.