This book evaluates new data on diet and cancer and uses it to update the dietary guidelines produced by ECP and IUNS in 1985. It is the proceedings of the 9th Annual Symposium of the European Organization for Cooperation in Cancer Prevention Studies held in Madrid during October, 1991. The first section updates general background material (dietary carcinogens, animal studies etc.), the second concerns diet and cancer at specific sites and also specific nutrients in human cancer. The third section addresses problems with guidelines per se, and the fourth the Mediterranean diet in relation to cancer. These chapters, together with the general conclusions reached in a parallel workshop, represent a state-of-the-art review of the current status of diet and cancer and also provide the background to the conclusions that guidelines as formulated in 1985 can no longer be sustained and that they need to be replaced by guidelines that (a) concern food groups instead of nutrients and (b) are targetted at particular groups rather than the population in general.