n the war on the cancer, the battlefield is uneven. Some cancers are common but mortality is relatively low. In other cancers, survival rates are high because screening programmes and treatments are effective. The greatest problem lies with cancers which affect millions of people yet survival rates remain very poor. The diagram below shows the change in 10 year survival rates for a range of cancers since 1971. Colon and lung cancer have a high incidence and stubbornly poor rates of 10 year survival despite 40 years of development. Today lung and colon cancer are still the world's biggest cancer killers - it is here that we can have the greatest impact.