Medical questions, medical dictionary, medical encyclopedia



What Is Cancer?


 

Example of one type of abnormal cancerous cell
Full size image

Cancer develops because cells in a part of the body begin to grow in an uncontrolled way and although there are many kinds of cancer they all start because of an out of control growth of abnormal cells.

Normal body cells grow, divide and then die in an orderly fashion.

When a person is young, the normal cells continue to divide more rapidly until the person reaches adulthood after which the cells in most parts of the body only divide in order to replace worn out or dying cells and in order to repair injuries.

What makes cancer cells different is that they continue to grow and divide and instead of dying they outlive the normal cells and continue to form new abnormal cells.

Cancer cells are thought to develop because of damage to a person's DNA and in most cases when DNA becomes damaged the body is able to repair it, but this is not the case with cancer cells.

It is possible to inherit damaged DNA which would account for inherited cancers but the damage is more frequently caused by exposure to something in the individual's environment, like smoking or bad diet.

Some cancer cells create a tumor whilst others like leukemia don't.

Cancer cells frequently travel to other parts of the body where they begin to grow and replace the normal tissue and this process is called 'metastasis'.

The names given to various forms of cancer are derived from the place where they begun and not from where they later moved to and continue to grow. Breast cancer, for example that spread to the liver would therefore be called breast cancer and not liver cancer.

Not all tumors are cancerous and the ones that don't spread are called benign and except in very rare exceptions they are not life threatening.

Cancer is the second leading cause of death in the United States and in the UK and it is estimated that one half of all men and one third of all women in those countries will develop cancer at some time during their lives.

There are millions of people in the world today that once had cancer or are presently living with it and the risk of developing most types of cancer can be greatly reduced by changes in a person's lifestyle.

Smoking is known to cause cancer and diet plays a major part.

So if you smoke, please stop!

Other articles:

Diet, and how it relates to cancer