The building blocks of our body are cells. The irregular and uncontrolled division and proliferation of cells is called CANCER. In the human body, cells divide in order to replace dead cells with new ones and to repair damaged tissues. However, this division has a speed and limit. With the loss of this spped and limit consciousness in cells, uncontrolled division and proliferation begin. These cells together form structures called tumorsand replace normal tissues. As the cancer increases, it can spread to other parts of the body. If cancer is limited to one area, it is called in situ, if it spreads in one area, is invasive, and if it spreads to other parts of the body is called metastasis. With the early diagnosis and correct treatment method, the spread of cancer to the human body can be prevented.