Breast cancer surgery types are generally still dominated by modified radical mastectomy. Modified radical mastectomy can be divided into two types; one preserves both the pectoralis major and pectoralis minor muscles, and the other removes the pectoralis minor muscle but preserves the pectoralis major muscle. Another option is breast-conserving surgery, which is feasible for tumors smaller than three centimeters and at least two centimeters away from the nipple. Nowadays, sentinel lymph node biopsy has become popular. If it proves that the sentinel lymph node has no metastasis, a single mastectomy can be performed.