Cancer
By: Venidikt • Essay • 1,976 Words • May 6, 2010 • 992 Views
Cancer
No other disease has much fear and horror in our everyday lives as cancer. Some statistics may explain that fear. Each year, over 1,250,000 new cases of invasive cancers will be diagnosed; more than 500,000 people will die from cancer; cancer causes one in five of all deaths; fifty percent of those diagnosed with cancer will die of the disease. As shown through the statistics, cancer is a medical phenomenon that is slowly taking over the world.
Cancer is not a modern illness. Evidence of cancer has been found in early years from fossils of animals and in mummified human remains. The word cancer comes from the Latin word crab, and its first known use was by Greek physician Hippocrates. Hippocrates and other early physicians did not understand the meaning of cells, but they did understand the idea that some abnormal growths were benign, or self-limiting, and some were malignant. Cells, however, were first seen by Robert Hooke in 1665, when he examined a piece of cork under one of the earliest microscopes. He named what he saw cells because he thought they looked like jail cells. Although, it is known that cancer has always been around for years, it is still unknown what the incidence of cancer was in early human life.
The cancer process, also known as carcinogenesis, usually takes two, three, or four decades to finally produce the cancer cell in the human body. Cancer is developed from the million of cells that are in the human body. Within each cell is a central core known as the nucleus, which contains the molecule deoxyribonucleic acid, also known as DNA. The DNA contains the genes that the cell needs to make the needed proteins for the human body. Abnormal chances in the cell’s DNA are called mutations; usually cells with mutation simply die. However, there are times they continue to divide at a rapid, uncontrolled rate to form clumps of cells that grow into the mass tissue that is called a tumor.
The mutated cells begin to multiply making primary tumors. A primary tumor establishes itself and also establishes energy supply that creates new blood vessels that steal vital nourishment from the liver. There are two main types of tumors: benign and malignant. Benign tumors are not cancer because the cells of non-mutated and do not bother the human body. Usually, benign tumors can be surgically removed or treated with drugs. The cells of the benign tumors do not spread through other parts of the body; once treated, the tumors do not come back. Malignant tumors are considered cancerous. Their mutated cells without control, and they can then damage and ruin the bodies tissues and organs. The cancer spreads by a process called metastasis causing the cancer cells also can break away from the malignant tumor and enter the bloodstream or the lymphatic system that forms new tumors in other organs. Then there are secondary tumors that do the same thing as primary tumors: they establish themselves in the organ and divert and cut off its energy supply. This creates large amounts of problems such as suppression of the immune system as normal metabolic function is damages, leaving the human to be exposed to different kids of infection, such as death of the organ and internal bleeding.
Cells are all around the human body. When cancer cells invade the human body, the first thing they do is establish energy supply. A cancer cells growth is usually planned; they are able to grow into very big cells, but are not able to stop growing once it has appeared. Cancer is a disease of cell replication, but when the genetic material from the cell is mutated, it fails. Cell division and replication is a fundamental aspect of life. Cancer occurs only in the cells that are replication; this is why the cancers that infect children and young adults are significantly different from those that infect adults.
The process that a cell turns into a mutant cell and then becomes a tumor consists of three essential overlapping phases: initiation, promotion, and progression. Initiation occurs when the cells is exposed to a carcinogenic, what is known as the cancer process, compound, happens usually in steps and over many years. There are many factors to the initiation process, such as, inherited genetic traits, viruses and bacteria (human papilloma virus and Helicobacter pylori), attacking agents (or carcinogens), etc. Promotion, the next stage, occurs once a cell has been initiated. During this phase, certain chemicals or biological conditions that have no appreciable cancer-causing activity on their own can greatly enhance or promote the formation of tumors when they are consumed or when they occur in the presence of an initiated cell. Tumor promoters tend to act indirectly by exerting an especially strong ability to cause cellular replication and intense changes in gene expression that alter controls on cell growth. Once the cell is initiated,