A breast surgical oncologist is a surgeon who specializes in treating breast cancer and benign diseases (non cancerous) of the breast. Breast surgeons in the United States have completed a surgical residency. Some breast surgeons have completed additional training, called a fellowship, which is dedicated to breast surgery or oncology. If your breast surgeon is not fellowship trained, remember that some surgeons started practicing before breast surgery fellowships were available. Even without a fellowship, specialized breast surgeons have dedicated their professional careers to the disease and perform hundreds of breast cancer surgeries every year. Your breast surgeon should have a comprehensive knowledge of cancer biology, genetics, and be able to provide you with the most modern surgical options to help you achieve the best results possible.