A cancerous growth is initiated when the growth of cells assumes uncontrollable dimensions. Quit the opposite of normal cells, these cells don’t die, but more and more abnormal cells are formed.
Mutations of the DNA of stem cells occur at random occasions, particularly when stem cells divide into different tissues. Such mutations can be a coincidence.
Mutations occur when a cell gets out of control and refuses to follow instructions coded in the genes. This is quite the opposite of the norm, when cell-reproduction and cell-growth is controlled by genes. This is the leading cause of cancer.
Stem cell mutations can not be prevented, this is the most depressing point. There must be at least half-a-dozen such mutations for it to be called a cancerous growth. Such mutations were found to be responsible for 22 types of cancer among the 31 studied.
There may be a mutation in some genes that leads to the production of a lot of proteins. They facilitate cell division. Alternatively, proteins programmed to instruct cells to stop division may not work, and the division process may go on forever.
It may be a long time before the cancerous growth manifests itself in the form of tumors. This is when comprehensive scan can detect the cancerous growth.
Mutations in genes are caused by a number of factors like consumption of tobacco. Cancer may even be hereditary in some people.
The truth is that genes get damaged and repaired as a normal process everyday. But damaged genes can build up in cells. The cell may not be in a position to repair the genes.