What is Cancer?

Cancer is a scary thought. Almost everyone knows someone who got very sick or died from cancer. Most of the time, cancer affects older people. Not many kids get cancer, but when they do, very often it can be treated and cured. Although many people have been affected by cancer, not everyone knows what it is. I wish to bring change to that with this article.

The human (and animal) body is made up of hundreds of millions of cells. Cells grow, divide, and die in an orderly fashion. Cancer begins when cells in a part of the body start to grow in a disorganized and uncontrolled manner. This is called analplasia. All cancer is started because of this. As cancer cells continue to grow and divide, a tumor forms, thus causing the invading and destruction of tissue at a rapid rate.

Cancer cells become cancerous because of abnormal nuclei. These abnormal nuclei are usually larger than they usually should be. This is caused by having too chromosomal irregularities, which may include: too many chromosomes, missing chromosomes, or missing parts of chromosomes. Because of these changes in the chromosomes, mutations occur. Mutations can lead to duplication of cells, deletions, gene amplifications, and extra copies of genes.

Normally, cells have a trait called contact inhibition. This is the property of a cell to cease division when in contact with neighboring cells or when growing in restricted space. Cancerous cells lack contact inhibition, therefore cancer cells pile into mounds.

Cancer cells would die quickly if not enough blood is supplied to them. Cancer cells induce vascularization (the formation of new blood vessels) and cause nearby blood vessels to form a capillary network which services the tumor. The most deadly aspect of cancer is its ability to spread, or metastasize. When a tumor becomes large, parts of it break off and go into the bloodstream, carrying cancerous cells to new locations and establishing itself there. The body has many safeguards to prevent cells from doing this, yet many cancer cells have the ability to overcome these safeguards.

A proto-oncogene is a gene that promotes the specialization and division of cells. They have many different functions in the cell. Some provide signals that lead to cell division. When these proto-oncogenes are mutated, they turn into oncogenes. Oncogenes contribute to the growth of a tumor, and can turn normal cells into cancerous cells. That process is call carcinogenesis. The process of carcinogenesis is started by initiators. Initiators are substances such as heavy metals in the oral cavity and radiation. They alter the cell DNA, which in turn causes the alteration of the cell reproduction process. Once the process is altered, promoters help the cancer cells to grow uncontrollably. Promoters are factors such as low dietary fiber and immune system suppressors.

Viruses can also be initiators for cancer. They act as agents that facilitate genetic changes in cells and make them cancerous. When the virus infects a cell, it inserts a part of its own DNA near the cell growth genes, causing cell division. The cells are made from this process are now special because on of the normal controls on growth has been lost. Some virus that can cause this carcinogenesis are HPV (Cervical Cancer), and hepatitis B (Liver Cancer).

Hopefully, after reading this article, you now know have a better understanding of cancer. Of course, cancer is much more complicated than I put it in this article, but the knowledge you have gained today should be sufficient for most practical circumstances. Let us all wait for the day that a cure for all cancers is discovered!

Sources:
Weinberg, Robert. The Biology of Cancer. 1st. New York, NY: Garland Science, 2006. 850. Print.

Massari, Francesca. Everything You Need to Know About Cancer. 1st ed. New York: The Rosen Publishing Group, 2000. Print.