Carcinogenesis

Carcinogenesis is the process of the emergence and development of malignant neoplasms (cancer). It includes three main stages: initiation, promotion and progression.

Initiation is irreversible damage to the genetic apparatus of the cell, leading to activation of oncogenes or inactivation of antioncogenes. This triggers uncontrolled cell growth. The initiators can be carcinogenic substances (for example, benzopyrene), ionizing radiation, viruses.

Promotion is the stimulation of proliferation of initiated cells. Promoters are substances that cause chronic inflammation and damage (asbestos, nickel). They create conditions for tumor growth.

Progression is the gradual transformation of cells into malignant ones. Additional genetic changes occur, and tumor cells acquire the ability to invade and metastasize.

Thus, carcinogenesis is a multi-stage process in which, under the influence of carcinogenic factors, normal cells turn into cancer cells. Understanding the mechanisms of carcinogenesis is important for the prevention and treatment of cancer.