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Cause of Cancer


Considering cancer is one of the oldest diseases of mankind, dating back to prehistoric ages, it is astounding that there is yet no real cure for cancer! Not only that, we have yet to fully understand what causes cancer in humans, and how to stop it.

The Egyptians have the earliest record of identifying and treating cancer as far back as 3000 BC. The Edwin Smith Papyrus describes 8 different types of cancer and mentions there is no cure for it. At the same time, it describes surgery and cauterization, which involved destroying tissue with a hot instrument called “the fire drill” as treatments used on tumors. Ancient Egyptians were able to distinguish between benign tumors from malignant (cancerous) tumors.

Edwin Smith papyrus

The ancient Greeks also made a detailed study of cancer, with Hippocrates being the first and perhaps the most significant. Hippocrates identified malignant and non-malignant tumors and likened its appearance to a crab, thus giving rise to the name cancer.  The Greeks also recognized that cancer was an extreme disease with very low chance of survival. Without understanding the origin of the tumor, the only advice ancient Greek doctors could give patients was to go home and die. According to the Greek humor theory, malignant tumors were caused by an excess of black bile, and could be cured only in the earliest stages. 

The Greek humor theory of cancer (like much of all medicine) continued well into the 16th century, without much progress in understanding or treatment of the disease. A number of pastes containing arsenic were developed to treat cancer but a cure or even significant treatment method remained elusive. The first new theory, the lymph theory, came in the 17th century when an Italian physician, Gaspare Aselli, discovered the lymphatic system and suggested that lymph abnormalities caused cancer.

Even then, it took years to make real headway into understanding the cause of cancer. In the late 19th century, the development of microscopes finally led to the cellular theory of cancer. It was finally discovered that cancer cells showed markedly different appearance and behavior than normal cells. Rudolph Virchow discovered that an abnormal increase in white cells caused a near-fatal blood disease, which he called “leukemia” and declared it a type of cancer. Thus came the discovery that abnormal cells are the most common cause of cancer.

Microscopic view of bone marrow of leukemia patient

Even so, there were conflicting theories on the cause of cancer, particularly because there are so many varied types of cancer. As recently as 1926, it was falsely believed that a worm caused stomach cancer, even fetching the scientist a Nobel Prize.

Only in the 20th century have we started seeing real advances in the understanding of the origin, cause and treatment of cancer. We now know that there are a number of causes including chromosomal abnormality, chemical and physical carcinogens, pollutants, diet, smoking, and even viruses that are responsible for different types of cancer.

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