What is cancer?

Cancer is not just one disease. There are more than 200 different types of cancer, depending on where in the body it starts. Cancer is a group of diseases characterized by unusual cell growth.

Our bodies are made of millions of cells and when cells are damaged, some of them may start to grow uncontrollably, crowding out healthy cells and spreading to other parts of the body. When this happens, we say the cancer has become malignant.

As we get older, the risk of damage to our cells increases. Specific genetic traits, certain viruses, and work-related or environmental exposures may also increase our risk. However, other risk factors are related to lifestyle choices such as tobacco use, alcohol misuse, unhealthy diet, physical inactivity, and unprotected sun exposure.