Breast cancer. Coloured magnetic resonance imaging (MRI) scan of the breast of a 56 year old woman with breast cancer. The malignant (cancerous) tumour (round, dark orange with white halo) has been highlighted by the contrast medium gadolinium. The white area around the tumour is a ring of necrotic (dead) tissue that is a result of rapid tumour growth. Breast cancer is the most common type of a cancer in women. Treatment is with the removal of the tumour only, where possible, or complete removal of the breast. Surgery is often combined with radiotherapy and chemotherapy.