Breast cancer. Side view of the chest of a 60 year old woman with cancer in her breast (upper right). The cancer is seen as a lump (tumour). Breast cancer is the most common type of cancer in women. The cancer can invade surrounding tissue and spread to other parts of the body (metastasis). It is usually detected by self- examination or mammogram before it gets to this advance stage. Treatment is with removal of the tumour only, where possible, or complete removal of the breast. Surgery is often combined with radiation therapy and chemotherapy.