What is Cancer?

Besides AIDS, Cancer is another deadly human disease of our times about which people are panicky all over the world. It is estimated that one in every three persons is a potential victim of cancer. Cancer is a disease resulting from an abnormal behaviour of cells in respected to their growth  and division during embryonic development, body growth, or regeneration and repair. Cellular growth and division occur under strict control of cellular genes. A cell which loses this control goes awry; It starts growing and dividing in an uncontrolled manner, forming an abnormal mass of similar cells in the concerned tissue.  This cell is a cancerous cell, and the mass of cells it gives rise to is called a tumour. This continues expanding and damaging neighbouring cells but, sooner or later. it generally becomes encapsulated in a fibrous capsule formed by the connective tissue around. Such     a localised tumour, called a benign tumor can be surgically removed .Thus unless a benign tumor becomes very large, it does not cause any significant discomfort to the patient.

If some cells  in an early tumor before encapsulation acquire further structural or functional abnormalities, these cells become invasive i e these break away  from the tumor, wander into the circulatory system and spread to distant sited in the body where these establish secondary tumours called metastases. The parent tumor is now called malignant. Such a tumor and its wandering cells are referred to as metastatic. The secondary tumors causes extensive damage to the tissues in   which these are formed, and this results into a full blown cancer causing death. A malignant tumor of connective tissue is called sarcoma.