The difficulty in treating cancer is that it’s not a single disease, but rather a group of diseases. In total there are more than 100 different types of cancers. Cancers are also caused by different things, so no one strategy can prevent them. Likewise, different cancers respond to different treatments, so no one treatment can cure them all. Treating cancer is further complicated due to the lifestyle and attitude of patients, the different physiology of people and the rate their bodies will metabolise drugs, the blood supply to the tumour affecting the drug getting into the tumour, the tumour physiology and the fact that the tumour can continue to change.