Tumor Evolution Is Directed by Cellular Responses to Survival Challenges

Tumor heterogeneity is a major obstacle in cancer therapy. We offer a novel perspective on tumor heterogeneity, informed by expanding upon the current view on tumor evolution. It is commonly known that in cancer, it is the advantageous genes and mutations that drive tumor capacities and the progression. We recognize an earlier, often overlooked, but necessary thus crucial step preceding the activation of advantageous genes functionality, namely, cellular response. We suggest that cancer is driven by an adaptive action taken by any organism when confronted with adversity - a cellular response to generate specific cancer capacities demanded to overcome survival threat - the responses that prompt the utilization of the functionality of advantageous genetic mutations and genes to attain these capacities and drive the disease. The ongoing development of cancer capabilities, as cells endeavor to obtain a competitive advantage, results in increased molecular chaos, observed as tumor heterogeneity. When the evolutionary drive for survival is impeded by therapeutic inhibition of critical genes, cell death occurs, a phenomenon thus termed oncogene addiction. We summarize the implications of this new framework for understanding tumor evolution and anti-cancer drug discovery, as well as understanding of basic cancer biology.