What causes cancer?
Anything that damages the genes in our cells can ultimately cause cancer, but a number of genes in the same cell need to be damaged before a cell becomes cancerous.
The vast majority of cancers are caused by DNA damage that accumulates over a person's lifetime ('sporadic' cancer). Cancers that are directly caused by genetic faults inherited from a parent are rare. For example, for every 20 cases of breast cancer, only one will be caused by an inherited mutation.
Things that can damage DNA include chemicals such as those in cigarette smoke, and radiation like ultraviolet (UV) light. People who have an unhealthy diet also seem to be more likely to develop cancer, although quite how a bad diet is linked to cancer risk is still a mystery. There are even some viruses are linked to cancer.
Increase text
Decrease text
Print this page
