The body is made up of millions of specialized cells that perform different functions critical to healthy body function. Among these cell types are skin, muscle, cardiac, skeletal, blood, liver, brain and lungs to name a few. Each cellular type performs special functions and is slightly different from the others.
Abnormal Cell Growth
Growth is a process that almost all cells perform. As they grow, the cells multiply and change in size. The genetic material in the cell specifies the type of cell it will be. But when something goes wrong and the DNA mutates, abnormal cell growth results. The cells no longer perform their particular function but become preoccupied with simply growing more and more cells. This atypical growth is how tumors develop. As the cancerous cells continue to grow, invade and spread, they can cause adjacent tissues and organs to malfunction.
Tumors
Generally there are two types of tumors, benign and malignant. The benign occur as capsule-like nodules with smooth edges and can be removed without serious consequences. The malignant tumors may have ragged surfaces and spread throughout the body with deadly results.
Melanoma
This is the most dangerous form of skin cancer. It is a malignancy of the melanocyte, the pigment-producing cell in the skin. Most commonly, it is found in fair skinned people and appears as a dark, mole-like structure with irregular edges. The risk increases with overexposure to the sun and sunburn.
Metastasis
The spread of cancer cells from the original site in the body to distant sites is a process called metastasis. This occurs when the cancer cells break away from the original growth mass or tumor and are deposited in another area of the body. Metastasizing cells are generally the same kind as those in the original tumor. If a cancer forms in the lung and spreads to the liver, those cells in the liver are lung cancer cells. The invading cells won't function as liver cells and only work to continue reproducing themselves and growing a useless mass in that organ.
Such a cancer continues to grow and spread in this manner and is much harder to treat. That's why it's so important to catch cancer as soon as possible.
Causes of Cancer
Various factors such as chemicals called carcinogens, radiation from the sun or from a nuclear source, and some viruses predispose cells to undergo cancerous changes. Also heredity, the environment and physical particles such as asbestos can lead to cell mutations.
Cancer Theories
The systematic, recorded study of cancer began in 1775 with a scientist named Pott, who observed that young men working as chimney sweeps showed an unusual frequency of scrotum cancer. He theorized that the tars in the soot and long exposure might have caused some changes in the body that led to cancer. Also he noticed that the exposure might take years before the cancer finally materialized and started growth.
Later, scientists fashioned several theories about cancer development. One is that the initial mutation or cell damage is preserved in the genetic materials of the cells. When the time is right, the memory activates; the DNA mutates and a transformation occurs within the cells.
Or perhaps viruses might take over the cell DNA and cause a change in cell function and growth at a later date-perhaps years later. Another theory is that environmental changes don't actually cause a direct mutation, but may allow otherwise normally functioning cells to misread other factors and change their operational modes.
The process is so complicated within the human body that no one treatment is sufficient to treat all kinds of cancers. The most common approach is to focus on the major cell type that is involved and treat the disease from that aspect. It becomes more complex when other organs and cell types become involved as the cancer metastasizes throughout the body and more treatments must be added to find a potential cure. Thus both the disease and the cure can become even more complex.
Additional List of Sources:
Timothy F. Meiller, D.D.S., Ph.D. CancerPenn Foster. 2008. Scranton, PA
www.en.scientificcommons.org/timothy_f_meiller
www.biomedexperts.com/concept.bme/14585/neoplasms
www.mayoclinic.com/health/housecall/housecalls&insecure=1&unsecure
Diane Evans - I am a retired civil engineer as well as a member of Sisters in Crime and the Society of Children's Book Writers and Illustrators.
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