The word cancer has considerable divergent meanings. Today in its most general form, cancer normally references a medical condition. The disease is categorized by a fatal tumor that is the by-product of unbound cell division. Oftentimes the disease advances to other parts of the body by way of the lymphatic system. If left untreated, cancer commonly results in death.

Cancer has clashed with people throughout recorded history. Fossilized bone tumors have been identified that beyond doubt show the presence of the disease thousands of years ago. The root of the word itself is credited to the Greek doctor Hippocrates (460-370 BC). Hippocrates is regarded as the "Father of Medicine." Yet, Hippocrates at no time used the word cancer. He used the words carcinoma and carcinos to describe tumors that were ulcer and non-ulcer forming. It wasn't until the Renaissance period and the 15th century that scientists began to call the disease cancer.

Cancer has three other major definitions, all of which antedate the condition of cancer. The first occurrence of the word cancer is found in Greek mythology. Cancer the crab was sent by Hera to harass Hercules in the course of his twelve labors. While Hercules was occupied fighting Hydra, a multi-headed monster, Cancer clamped onto the toe of Hercules with his claws. Hercules stepped on Cancer and killed him with his foot. Cancer's short life ended here. Nothing else is known about Cancer the mythical crab.

This brings us to our second occurrence of the word cancer. Hera was pleased with Cancer's sacrifice and lifted him into the heavens. He became the constellation Cancer, but was given weak stars since he didn't win against Hercules. The twelve labors of Hercules are ascribed to the Greek poet Peisandros of Rhodes. The poem is generally thought to have been written about 610 BC.

Lastly, we arrive at the third occurrence of the word cancer. After Cancer's ascension into the heavens and thus beginning his reign as a constellation, Cancer becomes the fourth sign of the zodiac in Astrology. The zodiac is an imaginary belt in the sky that amounts to about eight degrees on either side of the ecliptic. The sun moves through the twelve signs of the zodiac during the tropical year. In ancient times, the sun was within the constellation of Cancer between June 22 and July 22. Tropical astrology is traditionally thought to have origins around 100 BC.

In closing, the word cancer first showed up in Greek mythology in the story of Hercules and his twelve labors around 610 BC. The usage of the word cancer in in regard to a constellation showed up sometime slightly after 610 BC. Cancer became a component of tropical astronomy around 100 BC. Cancer then started to be used to characterize the medical disease of unbound cell division around 1400 AD.