The role of experimental research in the study of the prevention of malignant tumours.

The author discusses the role of experimental oncological research in the prevention of malignant neoplasms, with special reference to the conclusions drawn from such research in the USSR. He points out that experimental research can contribute to cancer prevention in two ways: (a) by supplying information on the occurrence of carcinogenic substances in the human environment-in the atmosphere, in industry and in foodstuffs-and thus providing a rational basis for the introduction of measures to prevent cancer from arising; and (b) by throwing light on the series of tissue changes that may precede the development of the malignant tumour and hence making it possible, through the timely treatment and cure of known precancerous conditions, to prevent cancer from developing.