Cancer is a disease in which cells of an organ or tissue in the body become abnormal, failing to respond to normal growth control mechanisms and continuing to grow and multiply out of control.
When cells grow out of control they usually form a mass, called a tumour. Some tumours grow and enlarge only at the site where they begin and these are referred to as benign tumours. Other tumours not only enlarge locally, but also have the potential to invade and destroy the normal tissue around them and to spread to distant parts of the body. These tumours are called malignant tumours or cancers.
Distant spread of cancer occurs when malignant cells become detached from the original (primary) tumour, get carried to other parts of the body through the blood or lymphatic vessels, and establish themselves in the new site as an independent (secondary) cancer. A tumour that has spread in this manner is said to have metastasized. The secondary tumour (or tumours) is called a metastasis (or metastases).
Since cancer may develop in any tissue of any organ, there are many different types of cancer. About 40% of women and 45% of men will develop cancer at some point during their life.
Source - http://bodyandhealth.canada.com
0 comments:
Post a Comment