Cancer is a term that is used to refer to a number of conditions where the body's cells begin to grow and reproduce in an uncontrollable way. This rapid growth of cancerous cells is known as a malignant tumor. These cells can then invade and destroy healthy tissue, including organs.

Cancer sometimes begins in one part of the body before spreading to other parts. This process is known as metastatis.

How common is cancer?

Cancer is a common condition and is a serious health problem, both in the US and across the world. It is estimated that 7.6 million people in the world died of cancer in 2007.

Types of cancer

There are hundreds of different types of cancer. The most common cancers are:

• breast cancer,
• prostate cancer,
• lung cancer
• cancer of colon, or rectum,
• bladder cancer, and
• ovarian cancer.

Risk factors for cancer include smoking, drinking alcohol, obesity, poor diet, lack of exercise, and prolonged exposure to sunlight.

Treatments for cancer include surgery, chemotherapy and radiotherapy. Some cancers can be cured if detected early enough.

Making some simple changes to your lifestyle can significantly reduce your risk of developing cancer. Eating a healthy diet, getting regular exercise, and avoiding smoking will all help to lower your risk of getting major health conditions, such as cancer.