What is Cancer?

All cells in the body contain DNA. DNAGenetic material inside the cell that tells the cell what to do and when to do it.Close It is DNA that tells the cell CellSmallest unit of all living organisms. Closewhat to do—when to grow and when to divide. Normally, cells in the body grow and divide at a controlled rate. However, when a cell’s DNA is damaged and the body is unable to repair it, the cell will begin to behave in an abnormal way and may:

• Grow uncontrollably
• Invade surrounding tissue
• Travel to other parts of the body (metastasize)
• Live longer than normal cells
• Attract blood vessels that help cancers to grow

This abnormal behavior of a cell is what is known as cancer (Figure 1). As these cells continue to grow, they may form a tumor, which is made up of many cancer cells grouped together. The development of cancer is a very complex process that usually takes many years.

Figure 1
A cancerous cell looks and acts differently from a normal cell (and may have molecules on its surface that are different in number or type from those on a normal cell).