What is Cancer?

Cancers claim more lives every year than any other disease, and come in many forms such as lung cancer, bowl cancer and breast cancer. Why are cancers so deadly and how can we treat them? Biology - Cells And DNA - Learning Points. There are over 200 types of cancer that affect different parts of the body. Cancer starts when a single cell is damaged due to lifestyle effects such as smoking or a bad diet. Apoptosis is the process by which a cell self-destructs when it is damaged, preventing cancer. If a damaged cell does not self-destruct, the single cancer cell may start to multiply uncontrollably and form a tumor. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.