The thought crosses everyone's mind at some time or other. Cancer is defined as abnormal cells with uncontrolled cell growth. It basically takes over the body one cell at a time. The ironic thing is that, often, cancer is curable, especially if detected at an early stage.
Tumors develop when abnormal cells start to grow out of control.
Tumors may be close enough to the skin to feel them, but not always. Cancer is not completely understood even in today's medical technology. Cancer usually begins in one specific area or organ, but it often metastisizes or spreads. Once it spreads, it is much harder to treat, that's why early detection is so important. It is possible to have cancer anywhere in the body, so if you suspect something, don't be embarrassed or afraid to go to the doctor.