Malignant transformation
Malignant transformation is the process by which cells acquire the properties of cancer. This may occur as a primary process in normal tissue, or secondarily as malignant degeneration of a previously existing benign tumor.
There are many causes of primary malignant transformation, or tumorigenesis. The underlying commonality is genetic mutation either by inheritance or more commonly by acquiring mutations in one's DNA over time. Although malignant transformation may occur because of changes within the cell, it can be induced by inorganic toxic substances such as cadmium or arsenite and organics such as tobacco-specific nitrosamines. It is also thought that some malignant transformations are due to viruses such as the Epstein-Barr virus, although this is currently restricted to just a few cancer types. A more common cancer associated with viral infection is cervical cancer, which has been linked to the human papilloma virus.