Genre: Information/Explanation

What causes cancer ? Cancer is abnormal cell growth , which is the result of damage - mutation - to certain crucial genes , the cell's instructions for making the proteins it needs to survive , grow and multiply . Many factors can affect the chances of the gene damage that may eventually lead to cancer , including cigarette smoke and other chemicals , a poor diet , ultraviolet radiation that causes sunburn , as well as some infections . Chemicals that cause cancer are called carcinogens . All these things can increase your risk of cancer . Digitalvision / Anna Lobbenberg / Science & Society Picture Library / Wellcome Photo Library