Using data on cancer incidence, Richard Doll and A B Hill of Oxford University School of Medicine, London, way back in 1950 linked lung cancer directly to cigarette smoking. Similar epidemiological studies conducted the world over have found how a diet rich in fats but lacking green vegetables can cause cancer of the stomach, colon, rectum and pancreas. Some examples:

• In parts of northeastern Minnesota, USA, there were a large number of cases of mesothelioma, a type of lung cancer associated with asbestos exposure. The state is now investigating occupation-related respiratory diseases, finding out whether mineworkers were exposed to asbestos.

• Latest data collected by the Western Australia Cancer Registry indicates that it had overestimated cancer cases for 1996-2001 The control interventions had been successful and contributed to a fall in the number of actual cases.

• In Kentucky, USA, the cancer registry data revealed that 35 per cent of women suffering from breast cancer came to the hospital only in the late stages, when survival chances are low. By enhancing the detection infrastructure, the registry was able to reduce the cases of late stage breast cancer to 30 per cent within two years. Along with saving lives, the interventions cut treatment costs by US $4.7 million.