Breast Surgeon
A breast surgeon is a surgeon who is specifically trained and skilled in operating on the breast. 
Breast Surgery Procedures
Breast surgeons perform the following surgeries for treatment of breast cancer:
Breast-conserving surgery.  When only the tumor and a portion of the surrounding tissues are removed, the surgery is called a lumpectomy, partial mastectomy, or quadrantectomy.  During a quadrantectomy, one-quarter of the breast is removed.
Mastectomy.  During a simple or total mastectomy, the entire breast is removed, but no underarm lymph nodes or muscle tissue is excised.  A modified radical mastectomy removes some of the lymph nodes as well.
Lymph node biopsy.  To detect whether or not the cancer has spread to the lymph nodes, a breast surgeon may also perform an axillary lymph node dissection or the newer, less invasive, sentinel lymph node biopsy, which uses lymph node mapping.
Radiation therapy.  New advances in radiation therapy are allowing breast surgeons to conduct partial breast irradiation by placing radioactive pellets inside the tumor cavity after breast-conserving surgery.  This procedure, known as Mammosite, allows for shorter treatments and fewer side effects for patients.
Breast reconstruction.  Several plastic surgery techniques can be used to reconstruct the breast after surgery for breast cancer.