DOCTORS HAVE WRITTEN about cancer since the dawn of recorded history. Descriptions of cancer can be found in the papyrus writings of ancient Egypt and the clay tablets of Babylonia.

Evidence suggests that a famous Greek physician named Hippocrates gave cancer its name about twenty-four hundred years ago. His writings contain the earliest known identification of the disease as carcinos, the Greek word meaning "crab." Experts think he chose that word because he saw that a cancerous tumor, or mass of cells, extends "fingers" of tissue into its surroundings. Tumors resemble crabs reaching out their pinching claws. Later, Roman writers translated this Greek word into their own word for "crab," cancer.

Although doctors knew about cancer a long time ago, they were seldom able to do much for people who had it. If a tumor was near the surface of the body and fairly small, surgeons could sometimes...