|
| |
 |
 |
|
Cancer results from a five-step process:
- An abnormal cell appears in the body.
- It divides and subdivides into new cells.
- The abnormal cells are of the type that can survive in parts of the body other than where they originated. These cells are called cancer cells.
- These new cells eventually form a clump, called a tumor.
- If unchecked, the tumor grows large enough to interfere with the delivery of nutrients and oxygen to nearby organs.
Benign vs. malignant tumors
There are two types of abnormal cells:
 Benign
This type of abnormal cell can survive only at its place of origin
and forms a tumor where it originates. A benign tumor, while
serious, can often be surgically removed, thereby ending the
problem.
Malignant
A malignant tumor is more dangerous because it cannot stop
dividing when it is supposed to and can thrive any place in the
body. The ability to travel and survive in other parts of the body is
called metastasis. Cancer cells form a tumor at the primary site
and also in places to which the cells metastasize.
Therefore, "cancer" is the generic name for over a hundred diseases that share similar characteristics of malignant cells. For cancer to be treated successfully, not only must the original tumor be controlled, but also the spread of disease (metastasis) must be stopped.
The immune system: our first line of defense
A leading contemporary theory states that abnormal cells may be in our bodies already as a normal course of our general health. The reason that these cells do not become cancerous may be that our immune systems are strong enough to destroy the cancer cells as they appear. Films have actually shown cancer cells being attacked and destroyed by immune system cells as if in battle. It is an inspiring sight. Some patients with cancer use that image to visualize their body responding in a proactive manner.
Our immune system is designed to protect the body from disease, abnormal cells, and "invaders" that enter through:
a break in the skin
food or other ingested matter
the air we breathe
the rays to which we are exposed
For cancer to take hold, the abnormal cancer cell appears when the immune system is not strong enough to rid the body of that cancer cell. One way to think about cancer is known as the immune surveillance theory. This view states that the cancer cell is not strong itself, but that the body's immune system is too weak to carry out its assigned job — removing cancer cells from the body.
|
|
 |
® 2008 Amgen All rights reserved.
