What is Cancer?

"Cancer" is an abnormal growth of cells anywhere in the body. It occurs when the genes in a cell allow it to split (make new cells) without control.
There are many kinds of cancer, because there are many kinds of cells in the body, and because there are many genes that control cell growth.
Some cancers form solid growths called tumors. Others, like cancers of the blood (leukemias) travel all over the body.
Cancers may harm the body in two ways. They may replace normal cells with cells that don't work properly, and they may kill normal cells.
Sometimes cancers stay put. Sometimes they spread to nearby organs. Sometimes they shed cells into the bloodstream or lymphatic system and travel to distant parts of the body.
The farther a cancer spreads, the harder it is to control. The distant spread of cancer, called "metastasis," is dangerous, because a number of vital organs may be harmed at once.
Many things may cause cancer by affecting the genes that control cell growth. The most common causes of cancer in Rhode Island are tobacco, unbalanced diets (diets with too much fat and red meat, and not enough fruits and vegetables), and too much sunlight. We can control many causes of cancer by making good choices in our everyday lives.
The National Cancer Institute has a book, Cancer Rates and Risks, which describes the major causes of cancer in the United States. The book refers to causes of cancer as "risk factors for cancer," because "risk" reminds us that getting cancer is "ify," not "certain," when we are exposed to things that may cause cancer.