Mortality

Mortality rates are the hardest and most important measure of progress because they are immune to the biases that inflate incidence and survival statistics: finding more harmless cancers raises incidence and apparent survival but does not reduce deaths. A screening test is only proven if it lowers disease-specific mortality in a randomised trial, as mammography, colonoscopy and low-dose CT for smokers have and PSA screening only marginally has; 'stage shift' is a surrogate for this. Cancer is now the leading cause of death in many high-income countries as heart disease declines, and global cancer deaths are rising with ageing populations even as age-adjusted rates fall.