Localized treatment that directly targets cancer cells by surgery or chemotherapy and radiation has not always been effective because of metastasis and recurrence of tumors. Whether the human body canbe considered an integrated ecosystem, using ecological analogy, is not clear. From an ecological perspective, the tissues and the organs are the niche of this ecosystem. The nutrients, space, and predators form an adaptive environment for somatic cells. Cancer cells are new species that possess different metabolic and reproductive strategies compared with the “resident” species population(somatic cells). These cells can invade a new habitat(tissues) at the right place and time, and successful invasion of an environment can result in the formation of a primary solid tumor. Once a tumor is formed, cancer cells modify their microenvironment(niche reconstruction) by changing the environment through glycolysis, secretion of growth factors, and recruitment of tumor-associated macrophages to promote cell growth, activate fibroblasts, and evade predation from the immune system. These actionshamper the eradication of cancer cells.
