Cancer is a group of diseases characterized by uncontrolled cell division and the ability of these cells to invade other tissues. It is caused by alterations to DNA (the genetic material) that are either inherited or acquired. If untreated, it is fatal, but many cancers can be treated and a significant proportion is cured.

I am at a speech meet. Cancer can cause many different symptoms, depending on the site and character of the malignancy and whether there is metastasis (spread). A definitive diagnosis usually requires the microscopic examination of tissue in the form of a biopsy. Once diagnosed, cancer is usually treated with surgery, chemotherapy and/or radiation.

Many cancers are preventable by avoiding environmental carcinogens or modifying behavior. Smoking tobacco is the largest preventable cause of cancer. Cancer is a prominent cause of death in many countries.