All organs in our body consist of cells. Cells are the smallest building blocks of our body and can only be seen with a microscope.

Healthy body cells (except muscle and nerve cells) have the ability to divide. They use these abilities to regenerate dead cells and repair injured tissues (inside and outside the body). But these abilities are also limited. They cannot be divided infinitely. Throughout its life, every cell has a certain number of divisibility. A healthy cell knows how to divide where and as much as necessary.

On the other hand, cancer cells lose this awareness, begin to divide uncontrollably and proliferate. Cancer cells accumulate and form tumors (masses). Tumors can compress, infiltrate or destroy normal tissues. If cancer cells break away from the tumor in which they formed, they can travel to other parts of the body through the blood or lymph circulation. Wherever they go, they form tumor colonies and continue to grow. This spread of cancer to other parts of the body is called metastasis.

Cancers are classified according to the organ in which they begin to form and their appearance under the microscope. Different types of cancer grow at different rates, show different patterns of spread, and respond to different treatments. For this reason, different treatments are applied in the treatment of cancer patients depending on the type of cancer they have.