It is estimated that one in 12 British women will develop breast cancer at some time in their life. A patient's chance of survival is high if the disease is diagnosed early on. Breast cancer is a malignant tumour that develops from cells in the breast. The disease occurs mostly in women, but can also occur in men.
Cancerous cells can enter the lymphatic system and move around the body, infecting other organs.
Breast cancers appear as a lump on the breast, but there are many different types of breast lump. Most are harmless, or benign, and are usually caused by damage to connective tissue, cysts or the build-up of scar tissue. Benign lumps are abnormal, but not life-threatening. Cancerous lumps can be either invasive, meaning the cancer has spread, or non-invasive, meaning it has not. Most women diagnosed at this stage can expect a full recovery.