Carcinogenesis typically occurs in three main stages: initiation, promotion, and progression.
Initiation This is the first stage where a normal cell undergoes genetic mutations due to exposure to a carcinogen. These mutations may affect genes that control cell growth, such as oncogenes and tumor suppressor genes.
Promotion During this stage, the initiated cells are stimulated to divide and proliferate. This stage is characterized by the selective growth of the mutated cells over normal cells, often driven by external factors like chronic inflammation or hormonal changes.
Progression In this final stage, the mutated cells acquire additional genetic changes that further enhance their growth and survival. This leads to the formation of malignant tumors that can invade surrounding tissues and metastasize to distant organs.
