Stomach Cancer Essays

Stomach Cancer Essays Stomach Cancer Essay Stomach Cancer Essay The human body is a complex system that has to be fully understood by us. It houses all the systems necessary for life. Each system works dependently with each other to sustain life. To acquire optimum body functioning, there should be a healthy relationship between the systems in our body.   Stomach, being part of the digestive system, holds a critical role in our body.   Like all the other organs in the human body, several alterations have been recorded that are considered threat to the human health. One of these is stomach cancer or otherwise known as gastric cancer. In order to understand what gastric is, it is imperative to determine first the anatomical and physiological structure of the stomach. This paper seeks to answer the following questions: 1.  Ã‚  Ã‚  Ã‚  Ã‚   What is a stomach? 2.  Ã‚  Ã‚  Ã‚  Ã‚   What is stomach cancer? 3.  Ã‚  Ã‚  Ã‚  Ã‚   What causes stomach cancer? 4.  Ã‚  Ã‚  Ã‚  Ã‚   Is stomach cancer caused by an individual’s genetic make up? 5.  Ã‚  Ã‚  Ã‚  Ã‚   Is stomach cancer caused by an individual’s environmental factors? 6.  Ã‚  Ã‚  Ã‚  Ã‚   How is stomach cancer diagnosed? 7.  Ã‚  Ã‚  Ã‚  Ã‚   What are the current treatments for stomach cancer? 8.  Ã‚  Ã‚  Ã‚  Ã‚   To which gender is stomach cancer most prevalent? 9.  Ã‚  Ã‚  Ã‚  Ã‚   To which race is stomach cancer most prevalent? The stomach is an expandable sack located mostly under the left lung, between the muscular diaphragm which pushes up the lung, and the coiled small intestine. The stomach is closed by important organs in the abdomen. To the right of the stomach is the liver, to its lower left is the spleen, and underneath it is the pancreas. The esophagus enters the stomach at the gastro-esophageal junction, while the small intestine exits it at the lowermost antrum. The front of the stomach rests on the abdominal wall, and lower parts of it also contact the upper left kidney and transverse colon. The important areas of the stomach itself are the greater curvature, the lesser curvature, the fundus and the cardia. The stomach has a delicate inner lining, made up of columnar epithelial cells, and acid secreting cells called parietal cells. The chemicals that protect this lining are called prostaglandins. The stomach has an impressive blood supply, mainly from the celiac artery which comes off of the main artery, the aorta. There is also venous drainage of blood to the spleen and liver. A secondary drainage system, called the lymph system, filters the blood in normally pea-sized lymph nodes. These are connected to lymphatics in other abdominal areas by lymph channels. Lymph nodes are full of white blood cells that help purify the blood serum; lymph nodes often enlarge when they detect spread of diseases. The point is that the stomachs rich blood supply and many drainage paths can act as conduits for spread of infections or cancers. The main purpose for the stomach is digestion of foods. Digestive process begins with the saliva in the mouth. In our diet, the stomach activates Vitamin B12, secretes hydrochloric acid to break down food, and churns the food into pulp. It can also directly absorb substances like alcohol and caffeine. The stomach is susceptible to an increase in the concentration of hydrochloric acid brought on by stress, certain foods, and the effects of tobacco smoke. While the stomach is normally protected against its own acid by an inner membrane, breakdown of this membrane leads to inflammation of the stomach, called gastritis.   An area that loses its membrane is also at risk to get an actual hole, called an ulcer. An ulcer may be shallow, and heal quickly, or it may be very deep and even perforate the outer stomach wall. Perforation is a surgical emergency. Fortunately, there are many medications now available which help reduce stomach acid concentration such as   Zantac, Pepcid and Tagame t, helping ulcers heal and preventing formation of new ones. Also, soothing protectants such as Carafate and even artificial prostaglandins can be given. These medications are often given preventively when the body is under great stress, such as after major surgery. While most stomach problems are minor ones, such as a mild virus or indigestion, occasionally serious disease strikes the stomach. The stomach is composed of various cells, which are intricately combined together into tissues which form the organ. These cells divide to produce new ones, and grow very rapidly during womb life, early childhood and puberty. In adulthood, new cells are produced only to replace those that die of old age, injury or disease. Normally, division of cells is under very tight control. This control is exerted by the genes inside each cell, which are housed in long clumps forming chromosomes, which are visible under a light microscope. The genes themselves are made up of DNA, the master genetic code material. If the genes are damaged, say by chemicals or radiation, the control over cell division may be lost in one particular cell. Ultimately, cancer is considered a disease of the DNA. Stomach cancer starts in a single lung cell. That cell starts dividing haphazardly, making millions and billions of copies of itself. It takes up the nourishment needed by other cells, depriving them so the can cer can continue to grow. Quickly growing cells can clump up to form a tumor. A tumor simply means a swelling; it can be caused by inflammation or infection. A benign tumor only grows in its local area it cannot spread and is not cancer. By contrast, a tumor which can spread to other body areas is called malignant and this is cancer. The process of cancer spread to other areas is called metastasis, so only malignant tumors such as cancer can metastasize. Theoretically, cancer can spread to any area of the body, and it often grows better in its area of spread than in its area of origin. It is this capacity for spread that makes cancer so dangerous. If not treated successfully, it ultimately kills by debility, anemia, infection, and compromise of normal body functions. The body is made up of many types of cells. Normally, cells grow, divide and die.  Sometimes, cells mutate and begin to grow and divide more quickly than normal cells.  Rather than dying, these abnormal cells clump together to form tumors. If these tumors are cancerous they can invade and kill your bodys healthy tissues. From these tumors, cancer cells can spread and form new tumors in other parts of the body. By contrast, benign tumors do not spread to other parts of the body. Stomach cancer, also called gastric cancer is the growth of cancer cells in the lining and wall of the stomach. There are 85% cases of gastric cancer which are   adenocarcinomas that occur in the lining of the stomach. Approximately 40% of cases develop in the lower part of the stomach (pylorus); 40% develop in the middle part (body); and 15% develop in the upper part (cardia). In about 10% of cases, cancer develops in more than one part of the organ. Stomach cancer can spread or metastasize to the esophagus or the small intestine, and can extend through the stomach wall to nearby lymph nodes and organs such as liver, pancreas, and colon. It also can metastasize to other parts of the body specifically the lungs, ovaries, bones. The American Cancer Society estimates that in 2006, about 22,280 new cases of gastric cancer will be diagnosed in the United States and that about 11,430 people will die of the disease. Most people diagnosed with stomach cancer are in their 60s and 70s. The majority of these people who are diagnosed with gastric cancer are more than the age of 65.   Stomach cancer is the second leading cause of cancer-related deaths. Carcinoma of the stomach is the most common form of gastric neoplasm and accounts for about 2.6% of all cancer deaths (Cancer Facts and Figures, 1991). Stomach cancer has decreased 5-fold in the U.S.A. over the past 50 years. It is more common in males, extremely rare in children, and the average patient is 55 years old. The cause of stomach cancer is unknown, but there are certain predisposing factors recognized. Genetic factors seem to be important, since gastric cancer is more common in persons with blood group A. Geographic of environmental factors appear to be important since gastric cancer is common in Japan, China, Chile and Iceland. The incidence rate in Japan is one of the highest in the world. There are studies that showed that Japanese immigrants to the United States have an incidence rate comparable to that of other Americans. Genetic or hereditary risk factors include hereditary nonpolyposis colon cancer (HNPCC) syndrome and Li-Fraumeni syndrome which are conditions that result in a predisposition to cancer. People with type A blood also have an increased risk for stomach cancer. Medical conditions that increase the risk for the disease include pernicious anemia which results from a vitamin B-12 deficiency, chronic inflammation of the stomach or otherwise known as atrophic gastritis and intestinal polyps. The most important environmental factors in the cause of gastric cancer are (1) salt added to food; (2) food additives such as nitrates, in pickled or salted foods such as bacon; and (3) food factors in water and vegetables such as Vitamin C. Dietary salt enhances the conversion of nitrates to carcinogenic nitrosamines in the stomach. Salt is also caustic to the stomach and can cause chronic atrophic gastritis. Finally, hypertonic salt solutions delay gastric emptying. Delayed emptying increases the time during which carcinogenic nitrosamines can exert their effects on the stomach mucosa. The metabolism of nitrates and nitrites is very complex. Nitrates interact with amino acids in the stomach to form nitrosamines. The conversion of those carcinogenic nitrosamines is enhanced at a low PH by iodides and thiocyanates. Nitrates are thought to be active only when converted to nitrites and to cause stomach cancer once atrophic gastritis has occurred. Stomach cancer usually begins in the glands of the stomach mucosa. Approximately, 50% of all gastric cancers develop in the prepyloric antrum. Atrophic gastritis and intestinal metaplasia are strongly linked to the development of gastric cancer. Insufficient acid secretion by the atrophic mucosa creates a relatively alkaline environment that permits bacteria to multiply and act on nitrates. The resulting increase in nitrosamines damages the DNA of mucosal cells further, promoting metaplasia and neoplasia. Duodenal reflux may also contribute to intestinal metaplasia. The reflux contains caustic bile salts to destroy the mucosal barrier that normally protects the stomach. There are three general forms of gastric carcinoma. Ulcerating carcinoma is the most common type and must be differentiated from a benign gastric ulcer. Polypoid carcinoma appears as a cauliflowerlike mass protruding into the lumen and may arise from an adenomatous polyp. Infiltrating carcinoma may penetrate the entire thickness of the stomach wall and is responsible for the inflexible â€Å"leather bottle stomach† or otherwise known as linitis plastica. The clinical manifestations of stomach cancer come in stages. The early stage is generally asymptomatic of produce vague symptoms such as loss of appetite, malaise and indigestion. Later manifestations of gastric cancer include unexplained weight loss, upper abdominal pain, vomiting, change in bowel habits and anemia caused by persistent occult bleeding. The prognosis is poor because symptoms do not occur until the tumor has penetrated the muscle layers of the stomach, spread to surrounding tissues and entered the draining lymph nodes and veins, causing distant metastases. Generally the first manifestations of carcinoma are caused by distant metastases. There are a range of choices by which stomach cancer is diagnosed. The choice of diagnostic tests depends on the clinical manifestation at the time of presentation. Most symptoms suggest a problem in the upper gastrointestinal tract. Direct endoscopic visualization and biopsy usually establish the diagnosis. Another definitive technique is microscopic examination of exfoliated cells obtained by lavage during endoscopy- an examination using a flexible viewing tube. Endoscopy is the best diagnostic procedure because it allows a doctor to view the stomach directly; to check for Helicobacter pylori-the bacterium that may play a role in stomach cancer; and to obtain tissue samples for examination under a microscope. The noncancerous stomach polyps are removed using endoscopy. If carcinoma is confined to the stomach, surgery is usually performed to try to cure it. Most or all of the stomach and nearby lymph nodes are removed. The prognosis is good if the cancer has not penetrated the stomach wall too deeply. In the United States, the results of surgery are often poor because most people have extensive cancer by the time a diagnosis is made. In Japan, where cancers are detected earlier by mass screening using endoscopy, the results of the surgery are better. If the carcinoma has spread beyond the stomach, the goal of treatment is to ease the symptoms and prolong life. Thus, chemotherapy and radiation therapy may relieve symptoms. Sometimes, surgery is used to relieve symptoms. For instance is when the passage of food is obstructed at the far end of the trunk, and out the right or left gastric artery. The bleeding site is identified by arteriography, after which a vasopressin infusion is started. Newer experimental methods include electrocuagulation, photocoagulation and application of polymers. At times when conservative methods fail, surgery may be the only method of treatment even though these patients are critically ill and poor surgical risks. The most effective surgical procedure is total gastrectomy, since these erosions are multiple or diffuse and tend to bleed again. The following data show the rate of incidence of cancers in the United States that have been evident not just for those who are whites, but also among the blacks, either female or male.   Please click this cancer.org/docroot/stt/stt_0.asp and attach them to the paper. I made it right like this coz it is difficult to paste the maps, graphs etc. to this order. From this site, you can download the maps and graphs which will show the incidence of gastric cancer not just in the US but worldwide. Indeed, there are several factors that predispose the onset of stomach cancer. Whether these factors are genetically based or have been caused by environmental factors, it is critical to be well-educated about stomach cancer. One could not directly conclude whether stomach cancer is caused by genetics or by the environment. In fact, studies have shown that all these factors can cause stomach cancer to an individual and may even worsen the condition, as the case there may be. Having enough knowledge as well as making the right treatment choices can make the difference of life or death. Understanding the causes and treatments of stomach cancer will help a person be conscious of his health. Through awareness, the whole population will get rid of the factors that might cause this cancer. By doing so, the incidence of stomach cancer will be lowered down and that good and sound health will already be acquired by the population, regardless of gender, race or socio-economic conditions.