The following is a list of common misconceptions regarding cancer to help you set aside pre-conceived notions of cancer before exploring the rest of the site.
Misconception: Cancer only occurs in elderly people.
Correction: Cancer can happen in any cell in the body at any time. Over the course of a long life the chances of developing a mutation that leads to cancer increase dramatically, but tumors can develop any time a harmful mutation occurs to convert a normal cell into a cancer cell.
Misconception: Cancer is a single disease
Correction: Cancer is a huge number of different types of diseases (over 100) that result from unique mutations in unique cell types throughout the body. All cancer behaves similarly but no two tumors are exactly alike, and tumors in different parts of the body, or in different patients, can have many, many differences.
Misconception: Cancer is always deadly
Correction: Cancer left untreated is always fatal, but with proper treatment the chance of survival for many types of cancer is quite favorable. Cancer research is always ongoing in the attempt to increase the effectiveness of treatment and improve the quality of life for those undergoing treatment for cancer.
Misconception: All tumors are cancerous
Correction: There are many mutations within cells that can cause them to grow more rapidly than surrounding cells and form tumors. However, it is possible for tumors to form without the ability to spread throughout the body and/or to form so slowly that human health is not negatively impacted. Such slow growing tumors are generally called "benign tumors" and are not considered cancer. In fact, moles are one common form of benign tumor that you probably have. The real danger from cancer comes from the speed at which it grows, which negatively effects surrounding organs and tissue, and its ability to expand through the bloodstream and begin growing new tumors in other parts of the body.
Misconception: "X Activity" causes cancer
Correction: Cancer is a complex disease that has many causes, and while many people would like to point to a specific activity or source as the "cause" of cancer that most that can ever be said is that certain activities can increase or decrease your *risk* of getting cancer, and generally only by small amounts. For a complete description of the causes and features of cancer read our page on the subject.