Q. How does a cell become cancerous?
Whatever the underlying causes are in a certain cancer one thing is always in common: All cancers start from a single cell that undergoes many changes. Some of those changes are permanent alterations to the DNA called mutations. When a mutation is able to reproduce itself without check then it becomes a cancer and spreads. This wild unchecked cell line then grows into adjacent tissues causing damage and injury to those tissues. Once this process of invasion starts cancer cells can spread via the bloodstream, and the lymphatic system, eventually causing death.