Introduction Cancer is a disease in which abnormal cells divide uncontrollably and destroy body tissue.Cancer cells grow uncontrollably and spread to other parts of the body. Cancer can start almost anywhere in the human body, which is made up of trillions of cells.Cancer is caused by mutations to the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide.Scientists have found that chronic stress can wear down our body's defenses,