Cancer is an uncontrolled proliferation of cells. This term is used for more than 200 different diseases in which abnormal cell (with abnormal chromosome from genetic change or damage) send wrong or different message from the one it should give. This cell grows rapidly, divides again and again without control and can invade adjacent tissues. It starts to form a lump which is called a malignant tumor. After many months, or years the lump can have a size that can be felt, seen on X ray or can cause pressure symptoms (pain, bleeding). For many of these cancers has no definite cause. If cancer is untreated can follow a fatal course.