A Mastectomy is when breast tissue if fully removed due to the presence of cancerous or pre-cancerous growth. The amount of tissue removed varies based on the size and stage of your cancer. More or less skin and/or the nipple may also need to be removed. Under certain circumstances, women with breast cancer have the opportunity to choose between total removal of a breast (mastectomy) and breast-conserving surgery (lumpectomy) followed by radiation. Although lumpectomy is the less invasive option and many women choose this route, deciding between lumpectomy and mastectomy depends on how you feel.