Malignant cells are characterized by alterations in multiple signaling pathways that promote proliferation, inhibit apoptosis, promote angiogenesis in the case of solid tumors, and enable cancer cells to invade and migrate through tissues. A variety of foods and their bioactive dietary constituents appear to have merit in reducing cancer risk and modifying tumor behavior. All of the major signaling pathways, which are deregulated in cancer, and which serve as potential targets for cancer prevention, have been reported to respond to one or more dietary components. Herein, we provide a brief overview of the importance of diet as a modifier of carcinogen metabolism, DNA repair, cell proliferation, apoptosis, inflammation, immunity, differentiation, angiogenesis, hormonal regulation and cellular energetics. This special issue of Current Cancer Drug Targets provides a collection of articles from researchers who are actively involved in examining the role of dietary components in cancer prevention and therapy. The remaining articles in this series provide more details about the specifics about the importance of these processes during carcinogenesis and proof-of-principal about the modifying capabilities of food patterns, specific foods and individual bioactive food components.