Breast cancer is the most common type of cancer in women, accounting for one in three diagnoses in the United States. Breast cancers are malignant, life-threatening tumors that develop in one or both breasts. The female breast is made up of fatty and fibrous connective tissues. The inside of the breast is divided into about twenty different sections called lobes. Each of the lobes is further divided into lobules, which are structures that contain small milk-producing glands. These glands feed milk into tiny ducts. These ducts carry milk through the breast and store it in a chamber located under the nipple. Breast cancer can be invasive (spread) or noninvasive (not spread). An invasive cancer penetrates the wall of a duct. This type of cancer is the most common and makes up about seventy percent of all cases. Infiltrating lobular cancer that spreads through the wall of a lobule accounts for approximately 8% of all breast cancers. This type is likely to appear in both breasts, often in seven separate locations. The cause of breast cancer is unknown, but researchers suggest that estrogen, a hormone produced by the ovaries, may be involved. Studies suggest that the longer a woman is exposed to the hormone (i.e. if she starts menstruating before age twelve or enters menopause after age fifty-five and/or has had children after age thirty) the equal to a greater risk. Two breast cancer susceptibility genes have recently been identified. The first is BRCA1 (a defect in this gene is common in those who have breast cancer) and the second is BRCA2 (a defect in this gene is associated only with breast cancer). People who have a mutated BRCA1 gene have an 86% risk of developing breast cancer by age seventy. Women are one hundred times more likely to get breast cancer than men. More than eighty percent of breast cancer cases occur in women over the age of fifty. By the age of forty its chances are one in two hundred and seventeen (217), and in women under the age of thirty they account for only 1.5% of all breast cancer cases. About 5% of all breast cancers are hereditary. Women with a family history of breast cancer in a first-degree relative (i.e., mother, sister, and daughter) are at two to three times the risk of the general population. Women taking hormones... center of paper... ....if the nipple has been removed it can be reconstructed from other body tissue and the color is applied using tattoo techniques. Recidivism is always a serious event. Relapse usually occurs in two to three out of ten cases. There are three ways breast cancer can come back. The most common recurrence is in the breast preserved in the region of the original cancer. If this type of cancer has not spread, it can be treated with a mastectomy. The other type of recurrence involves the lymph nodes. If it is not considered a metastasis (spread to other areas) it may be treated with further surgery or radiation therapy. A recurrence in the scar or chest wall after a mastectomy is more serious. Since all the breast tissue has been removed, it is impossible for the cancer to be residual and therefore must have traveled from the lymphatic system or bloodstream. In conclusion, it is very important for women to perform daily/monthly breast exams and, if age (40 years or older) or if the woman has specific risk factors, it is necessary to perform a mammogram on an annual or semi-annual basis. With all the medical advances today, it is hoped that a cure for breast cancer can be found in the near future.