Carcinogenesis and Mutagenesis
Carcinogenesis is the formation of a cancer, whereby normal cells are distorted into cancer cells. The process is characterized by changes at the cellular, genetic, and epigenetic levels and abnormal cell division, in some cancers developing a malignant mass. Cell division is a physiological procedure that occurs in almost all tissues and under a variety of circumstances. A mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer, mutagens are therefore also likely to be carcinogens, although not always necessarily.