Epidemiology

 Cancer epidemiology is the study of the incidence of cancer as a way to speculate possible trends and causes. The first cause of cancer was identified by British surgeon Percivall Pott, who discovered that cancer of the scrotum was a common disease among chimney sweeps.

 Janet Lane-Claypon published a comparative study of 500 breast cancer cases and 500 controlled patients, with the same background and lifestyle for the British Ministry of Health. Her impressive work on cancer epidemiology was carried on by Richard Doll and Austin Bradford Hill, who published "Lung Cancer and Other Causes of Death In Relation to Smoking.

With appearance of computers, the Oxford unit for Cancer epidemiology was the first to compile large amounts of cancer information. Modern epidemiological methods are closely linked to current concepts of disease and public health policy. Over the past 50 years, great efforts have been spent on gathering data across medical practice, hospitals and even country boundaries, as a way to study the influence of environmental and cultural factors on cancer incidence.

 In some Western countries, such as the USA and the UK cancer is overtaking cardiovascular disease as the leading cause of death. In many Third World countries cancer incidence appears much lower, most likely because of the higher death rates due to infectious disease or injury. With the increased control over malaria and tuberculosis in some Third World countries, incidence of cancer is expected to rise.