Epidemiology of cancer: spatial-temporal aggregation.

Studies of spatial and temporal distribution patterns of cancer in man and in ani mals have yielded much information and have identified many topics for more in tensive, more rigidly designed epidemiologic investigations. In fact, the wealth of such leads makes the determination of priority and the logistics of the research inn portant considerations. In addition to specific investigations, long-term ecologic observations of cancer in human and animal populations are to be encouraged. There are also unexploited opportunities in experimental cancer epidemiology that deserve biometrically con trolled studies.