Our bodies are made up of thousands of cells. In a healthy person, new cells are made only when the body needs them. In a person with cancer, the abnormal cells destroy the normal cells, invading them like an army. If cells divide when new cells are not needed, a growth or hard mass forms. It could be small like a pea or large like a grapefruit. A cancerous growth is called a malignant tumor.
Cancer usually kills a person when it spreads to other parts of the body. Sometimes cancer cells break away from a malignant tumor and find their way into the bloodstream. They travel to another part of the body or organ like a kidney or lung. There they start multiplying and dividing and form new cancerous tumors. For example, if a woman who has a malignant tumor in her breast does not have it removed while it is small, part of the tumor might break away and go into her bloodstream. From there it may travel to her brain and give her brain cancer.
Chemicals in cigarettes and ciga