Causes of Mutation

As we have seen, cancer cells are created from normal precursor cells via an accumulation of genetic damage. The mechanisms by which the changes are induced is varied. In a broad sense, the agents of genetic change (mutation) fall primarily into the categories described below and are discussed in depth on the following pages.

• Spontaneous Mutations - mutations resulting from unrepaired replication errors or random molecular events
• Induced Mutations - mutations caused by things such as radiation, chemicals, chronic inflammation, and oxygen radicals.
• Abnormal Cell Division - problems in cell division can result in mutations
• Viruses - a significant percentage of cancers are caused by viruses.  Viruses can directly damage DNA, acting like mutagens,  they can alter the behavior of the infected cells or they can induce changes in nearby cells, indirectly leading to cancer.

The animation below shows some of the causes of DNA damage (mutation).