What is a mastectomy?

A mastectomy is a surgical procedure that involves the removal of the entire breast, typically as a treatment for breast cancer. This procedure may be performed to eliminate cancerous tissue and reduce the risk of the disease returning or spreading. The choice to undergo a mastectomy can be influenced by various factors such as the size and location of the tumor, the stage of cancer, and the patient's medical history and preferences.

Understanding this context clarifies why the correct answer is the one focusing on the complete removal of the breast rather than just a tumor, which would be a different surgical procedure like a lumpectomy. Additionally, options involving radiation therapy and chemotherapy refer to non-surgical treatment modalities that may be used in conjunction with or instead of surgery, but they are not surgical procedures themselves.