Cancer is a word that strikes fear into most people, but most people really don't know what cancer actually is.
To understand cancer it first helps to understand what normal cells do. Your body produces about 500,000 new cells for growth and repair every day. Normal cells reproduce themselves exactly and they stop reproducing at the right time. Cell division has rules and normally cells will destroy themselves if they are damaged.
Cancer cells do not obey the rules of cell division. Cancer cells will not destroy themselves if they are abnormal, they do not stick together or become mature, they do not obey signals from neighboring cells and they keep on reproducing. What results is an abnormal mass of cells that we call a tumor. A tumor is often made up of billions of copies of the original cancer cell.
There are two types of tumor, benign and malignant. Benign tumors reproduce in a fairly orderly way, they are encapsulated, do not invade normal tissue, do not spread to other parts of the body and are rarely fatal unless they exert pressure on other organs (i.e. brain tumors). Malignant Tumors are very different from the cells of the surrounding tissue. They invade and destroy tissue around them. Their growth is more rapid than the tissue around them and bits of the tumor, called metastases, can break off from the primary growth and spread to other parts of the body forming other tumors.
The grade of cancer will influence the planning of treatment and help estimate a treatment outcome. Tumors are graded 1-4. The lower the grade of the cancer denotes a less aggressive form. Grade 3 and 4 cancers are usually more aggressive and invasive.
