Most patients with breast cancer have surgery to remove the cancer from the breast. Usually some of the lymph nodes under the arm are also taken out and looked at under a microscope to see if there are any cancer cells. Different types of operations are used. It is usually followed by radiation therapy to the part of the breast that remains.
Most doctors also take out some of the lymph nodes under the arm.
Partial or segmental mastectomy is the removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually some of the lymph nodes under the arm are taken out. In most cases, radiation therapy follows. Sometimes lymph nodes under the arm are also taken out. This is the most common operation for breast cancer.