Breast cancer is cancer is formed in the breast cells. Breast cancer can occur in both men and women, but it's far more common in women .Symptoms of breast cancer may include a clot in the breast, a change in breast shape & size, concavity of the skin, fluid coming out from the nipple, a newly flip nipple, or a red spot on skin. Breast cancer begins with cells in the milk-producing ducts (invasive ductal carcinoma). Breast cancer begins in the glandular tissue are called lobules (invasive lobular carcinoma) or in other cells or tissue within the breast.