The phenotypes of cancer and aging are in many instances contrary. Cancer cells do not "age", their metabolic, proliferative, growth and signalling characteristics are opposite to those observed with cellular aging (both replicative and functional). That is, cancer manifests itself as local uncontrolled "rejuvenation" in an organism. Available data suggest that the opposite phenotypic features of aging and cancer arise from the alternative regulation of the same genes particularly related to apoptotic and growth signal transduction pathways. Genes normally managing cellular aging promote cancer when contrarily regulated. For example, permanent expression of p53 is needed to keep senescent cells in the state of irreversible growth arrest, while downregulation of the same p53 favors cancer development. We propose that controlled expression of various cancer genes may have anti-aging effect not only on cells but also on an organism and discuss experimental evidence supporting this view.