Cancer happens when cells in the body begin to grow and don't stop. Normal cells grow in a uniform way and cancer cells don't. They continue to grow and push out the normal cancer cells. There are many kinds of cancer but all cancer has this fact in common. The fact they have this "out-of-control" abnormal growth.

There are a lot of different types of cancer and all of these cancers will act very differently. They can grow at different rates and respond to treatment uniquely. It is very important to make sure you treat the different cancers with the correct treatment for that type of cancer.

Cancer cells can break away from a tumor (cluster of out of control cells) and spread to other parts of the body using the blood or lymph system to travel. They can then start attacking new parts of the body forming new tumors. This is then called metastatsis. Metastatsis is what this is called when cancer spreads throughout the body in this way.

Although cancer can spread to other parts of the body, it is still named after the original body part where it all started. For example if the your cancer started in your lungs and spreads to your liver, it is still referred to as lung cancer. Sometimes cancer can come back in a person who was told they were clear and free of the disease after treatment, this is called a recurrence. The chance of a recurrence happening depends on many factors including patient family history, type of cancer and lifestyle.