Explain the Development of Cancer?

Are you interested in knowing how cancer develops? Well here it is. The cancer development is a process involving initiation, promotion and progression as highlighted in Figure. The first step is initiation when the exposure to a carcinogen allows the carcinogen to enter the cell. This carcinogen then alters the cellular DNA (de-oxyribo nucleic acid). The second step is promotion when there is enhancement of cancer development and the cell begins to multiply uncontrolled. The third step is known as progression when a tumour formation takes place. It may spread to other tissues or organs. Thus the cells released and carried to other parts of the body are called as metastasis.

Figure: Steps in development of cancer

We should remember that cancer development is a process and not a single event. The initiating event may be either chemical or physical. The chemical event may occur when a carcinogen intrudes into the cell and alters the genetic material. The physical event may occur when radiation bombards the cell and alters the genetic material. Whatever is the reason, the protein making machinery of the cell changes so that the DNA produces an odd structural protein. Then the cells begin to multiply out of control forming a tumor. In this context, let us get to know what are carcinogens.