Cancer Research Articles

Cancer - An introduction

What is cancer?

Cancer is a term used to describe a group of diseases which result from uncontrolled and abnormal growth of cells in the body. The reason for this uncontrolled and abnormal growth is due to damages to the DNA, present in every cell in the body, also called mutations. For this reason cancer can be said to be a genetic disease.

How cancer occurs

In a normal human being cells grow, divide and die in an orderly fashion with new cells replacing old and damaged cells. The death of aged and damaged cells is controlled by a genetic program called Apoptosis (progrmammed cell death). DNA, which is present in every cell and controls all it's activity, is responsible for the control of this orderly process.

Sometimes this orderly process goes wrong,due to damage to the DNA. Cells have mechanisms to repair damaged DNA and most of the times the damages are repaired and if the repair mechanisms fail to repair the damaged DNA the cell undergoes Apoptosis. In cancer the damaged DNA is not repaired and the cells don't die but continue to survive and proliferate leading to a mass of cells called tumors. Most of the cancers form tumors,but sometimes,like in leukemia, which is cancer of the blood cells, there is no tumor and the cancer cells circulate in the blood stream and spread to various organs in the body. Not all tumors are cancers. Tumors which are not cancerous are called Benign tumors. Cancerous tumors are called malignant tumors.

As mentioned above damage to the DNA leads to tumor formation. The changes in DNA which cause the cell to become cancerous are called mutations. These mutations can be inherited(from one or both the parents) or acquired. The presence of inherited mutations doesn't mean that the person is going to be affected by cancer. But the chances of the person developing a cancer are increased. Many individuals with inherited DNA changes don't develop cancer. A single mutation is usually not sufficient to cause cancer as multiple mutations are usually required for the cells to become cancerous. Mutations can also be acquired in one's lifetime by exposure to radiation, carcinogens like cigarette smoke, asbestos, tobacco etc and faulty DNA repair