Cancer is a disease of the body in which abnormal cells multiply out of control.
There are many types of cancer and they are normally named after the part of the body where the cancer first developed.
If cells in the breast become abnormal they may multiply and grow faster than normal healthy cells.
Collectively these abnormal cells can form a tumor – a mass of abnormal cells.
Breast cancer starts in the breast and is more common in women than in men.
If breast cancer spreads to other parts of the body it is called metastatic or secondary breast cancer (see types of breast cancer).
There are numerous tests for breast cancer. Each test carries different degrees of accuracy and more than one test is often used to confirm diagnosis.
Prognosis and survival rates for breast cancer vary depending on the stage the breast cancer was treated. The prognosis for early stage breast cancer is good and survival rates are high with many women enjoying fullfilling long lasting lives after treatment.
Survival rates for later stage breast cancer are lower. By stage 4, breast cancer cells have spread to different parts of the body. Stage 4 treatment focuses on reducing pain, and prolonging life rather than eliminating the cancer altogether.