Gastric Cancer Prevention - Essay Example

Gastric Cancer Prevention: Importance of mass and high risk screening in the face of demographic changes in the U.S. Introduction: According to Tan and Fielding 2006, “gastric cancer is generally accepted as a multi-step progression disease from chronic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia and subsequently to cancer. Infection with Heliobacter pylori has been linked to gastric carcinogenesis”. Chronic atrophic gastritis is a predisposing factor for gastric cancer, such that it has become generally accepted that if there is no chronic atrophic gastritis present, there is no gastric cancer. (Genta, 2004). Heliobacter pylori infection has been accepted as the causative factor for most gastric cancers (McColl, 2005). Dietary factors have been associated with gastric cancer. There is evidence to suggest that a dietary intake of salty foods and N-nitroso compounds and a low dietary intake of fresh foods and vegetables elevate the risk for gastric cancer. There is also evidence to show that tobacco and obesity are risk factors for gastric cancer. The other known risk factors for gastric ulcer are radiation, pernicious anemia, blood type A, previous gastric surgery for benign conditions, and Epstein-Barr virus. Previous family history where genetic syndromes such as hereditary nonpolyposis colon cancer and Li-Fraumeni syndrome have been involved are considers as significant risk factors (Crew & Neugut, 2006). Epidemiology: In spite of the marked fall in gastric cancer cases world wide over the last seven decades, it still remains a major health concern, as it is the fourth most common cancer, and is the second highest cause for cancer related deaths world wide. In the first year of the new millennium nearly 880,000 people were diagnosed with gastric cancer around the world, and gastric cancer related mortality worldwide was about 650,000(Crew & Neugut, 2006). The developing countries in Asia, south-eastern Africa, eastern South America, and some areas of Western Europe are high risk areas for oesophageal cancers, while in the Western world gastrooesophageal cancers are on the rise. The developing countries in Central and South America, eastern Asia and Europe, and Japan are high risk areas for stomach cancer. (Rozen, 2004). Incidence of gastric cancer demonstrates wide variance based on geographic locations. The Western industrialized including the United States of America are geographic areas with the lowest rates for gastric cancer (Lynch, Grady, Suriano & Huntsman, 2005). In the United States of America gastric cancer is responsible for 5.2 deaths per 100,000 of population, whereas in a high risk country like Japan Gastric cancer is responsible for 90 deaths per 100,000 of population (Hohenbeger & Gretchel, 2003). In the U.S.A the incidence of gastric cancer is low, which demonstrates the change in the pattern of gastritis from atrophic to non-atrophic, and also the low and reducing prevalence of H pylori infections among the middle and upper classes of society (Graham & Shiotani, 2005). In New York every year around 15,000 people die every year as a result of cancer. Gastric cancer ranks among the top ten causes for cancer. Gastric cancer among the immigrants in New York is higher than native born citizens in New York (The Health of Immigrants in New York City). Change in Demographics: The male-to-female ratio for noncardia gastric cancer is 2:1, while the ratio for gastric cardio carcinomas 5:1. Noncardia gastric cancers have significantly higher incidence rates among the black and lower socio-economic segments of society. Age is also a relevant factor in the incidence of gastric cancer, with the highest incidence seen in the age group fifty to seventy. Professional classes witness a higher incidence of proximal gastric cancers. These incidence rates have significance for the importance of screening for gastric cancer in the U.S. Life expectancy has increased there is a significant higher proportion of older population in the U.S. With the a high incidence for gastric cancer in the fifty to seventy age group, the probability of enhanced gastric cancer incidence is high, and particularly so in the high risk population segments of males among the black and lower classes of the population (Crew & Neugut, 2006). Immigration into the United States from the developing countries around the world, with particular emphasis on the regions where there is a high prevalence of gastric cancer is continuing exercise. These immigrants from Asia, South America, and Eastern Europe present a high risk population for gastric cancer (Rozen, 2004). Gastric Cancer Screening: The rationale behind gastric cancer screening is that it allows for early detection of cancer. Early detection of cancer helps in reducing the mortality that results from gastric cancer (Graham & Shiotani, 2005). In Japan for nearly fifty years a mass nation wide screening has going on using photofluorography. Photofluorography makes use of double-contrast barium mal studies of the stomach with the assistance of seven principal views. Every year it is estimated that more than six million people have been screened through the mass screening program employing photofluorography in Japan, and is considered one of the reasons for the decline in the incidence of gastric cancer in Japan (Suzuki, Gotoda, Sasako & Saito, 2006). However it is found that mass screening programs using photofluorography is not as efficient as individual screening programs using systemic endoscopy (Miki, 2006). Recently the introduction of the serum pepsinogen test method has been employed in Japan, as a means of increasing then efficiency of mass screening for gastric cancer, as it is found to be a useful as a mass screening tool in high-risk subjects with atrophic gastritis (Miki, Morita, Sasajima, Hoshina, Kanda & Urita, 2003). The pepsinogen test method uses the generally accepted principle that serum pepsinogen concentrations are related to gastritis, and gastric mucosal lesions, with the special relationship to chronic atrophic gastritis. Chronic atrophic gastritis is known to be the preceding condition in the chain of histopathical conditions that lead to gastric cancer, and hence serum pepsinogen test has grown to be used in more than twenty countries worldwide (Miki, 2006). Photofluorography, endoscopy and the pepsinogen test methods target the presence of either the conditions that lead to gastric cancer or the early detection of cancer itself. The knowledge that Heliobacter pylori infections is the causative factor for gastric cancer has ked to the use of the detection of the presence Heliobacter pylori, as a screening means in the prevention of gastric cancer (Moayyedi & Hunt, 2004). Heliobacter pylori screening is a useful means to screen high risk populations in countries like the United States of America, where the incidence of gastric cancer in the general population is low, when compared to high incidence countries like Japan (Parsonnet, Harris, Hack & Owens, 1996). Clinical Importance and Relevance of Screening: The important aspect of screening for gastric cancer is that it leads to a significant reduction in mortality as a result of gastric cancer (Lee, Inoue, Otani, Iwasaki & Sasazuki, 2006). This means that screening of gastric cancer reduces the economic costs of gastric cancer, through the reduction of mortality rates. Therefore any comparison of cost of screening and cost of treatment needs to take this aspect into consideration. The cost-effectiveness of gastric cancer screening is dependent on the level of incidence and the cost of the screening procedure. In a country like China, where the incidence is high the cost effectiveness is much greater than it would be for a country like the U.S. with a low incidence rate for gastric cancer (Chan & Wong, 2006). Screening for gastric cancer is particularly cost effective in a country like the United States targeting high risk groups. An analysis of the cost-effectiveness gastric screening using helicobacter pylori screening method suggests that 11,646,000 people in the U.S. could be screened and treated for a cost that works out to $996 million. The cost effectiveness was calculated as $25,000 per life saved. The cost-effectiveness of any mass screening program, is based on the sensitivity and the expense of the cancer prevention strategy. The efficiency goes up when high risk groups like Japanese- Americans are the target of the gastric screening program with the cost for screening and treatment working out to be less than $50,000 per year of life saved, even when the efficiency of treatment was five percent (Parsonnet, Harris, Hack & Owens, 1996). Current Research and Guidelines: There is enough evidence to show that mass screening for gastric cancer reduces the mortality rates as a result of gastric cancer (Miyamoto, et al, 2007). However, mass screening practices are more efficient in countries that have a high incidence of gastric cancer. Developed countries like the U.S. with a lower incidence of gastric cancer need to target high risk segment of their population for the mass screening programs to be cost effective. (Chan & Wong, 2006). The advantage with the use of the helicobacter pylori screening method is that it is focused on the causative factor of the helicobacter pylori, which is the precursor of gastric cancer and hence acts at the first level of the chain of gastric cancer. (Moayyedi & Hunt, 2004). There is evidence to show that targeting helibacter pylori reduces the incidence of gastric cancer(Parsonnet, Harris, Hack & Owens, 1996). Initiatives Required: Mass screening for any dreaded disease like cancer involves a lot of money. Therefore the initiative needed from the governmental authorities is the budgetary allocation of the required funds and motivating the public health system towards the objectives of the mass screening programs. NGOs have the capacity for promoting mass screening programs, through interacting with high risk segments of population and creating awareness of the mass screening programs and the benefits that ensue to these high risk target groups (The Health of Immigrants in New York City). At the primary care level detailed history and lab tests would identify individuals with high risk for cancer with atrophic gastritis or pernicious anemia, those who have undergone partial gastrectomy , those with a sporadic gastric adenoma, immigrant ethnic populations from countries with high rates of gastric cancer, and patients with familial adenomatous polyposis or hereditary nonpolyposis colorectal cancer (Chan & Wong, 2006). Prevention: Mass screening prevention programs targeting high risk segments of population as a result of age, socio-economic class, and ethnicity. Through this identification the risk for gastric cancer can be reduced by promoting healthy life styles. Literary References Chan, A. O. O. & Wong, B. C. U. (2006). Screening for gastric cancer. Retrieved April 15, 2007, from, UpTodate. Web site: http://www-dep.iarc.fr/ Crew, K. D. & Neugut, A. I. (2006). Epidemiology of gastric cancer. World Journal of Gastroenterology, 12(3), 354-362. Genta, R. M. (2004). Screening for gastric cancer: does it make sense? Aliment Pharmacol Ther, 20(Suppl.2), 42-47. Graham, D. Y. & Shiotani, A. (2005). The time to eradicate gastric cancer is now. Gut, 54, 735-738. Hohenbeger, P. & Gretchel, S. (2003). Gastric cancer. Lancet, 362, 305-315. Lee, K., Inoue, M., Otani, T., Iwasaki M. & Sasazuki, S. (2006). Gastric cancer screening and subsequent risk of gastric cancer: A large-scale population-based cohort study. Int. J. Cancer, 118, 2315-2321. Lynch, H. T., Grady, W., Suriano, G & Huntsman, D. (2005). Gastric cancer: new genetic developments. Journal of surgical oncology, 90(3), 114-133. McColl, K. E. l. (2005). Screening for early gastric cancer. Gut, 54, 740-742. Miki, K. (2006). Gastric screening using the serum pepsinogen test method. Gastric Cancer, Miki, K., Morita, M., Sasajima, M., Hoshina, R., Kanda, E. & Urita, Y. (2003). The American Journal of Gastroenterology, 98(4), 735-739. Miyamoto, A. et al. (2007). Lower risk of death from gastric cancer among participants of gastric cancer screening in Japan: A population-based cohort study. Preventive medicine, 44, 12-19. Moayyedi, P. & Hunt, R. H. (2004). Heliobacter pylori Public Health Implications, Heliobacter, 9, (Suppl. 1), 67-72. Parsonnet, J., Harris, R. A., Hack, H. M. & Owens, D. K. (1996). Modelling cost-effectivenessof Heliobacter pylori screening to prevent gastric cancer: a mandate for clinical trials, Lancet, 348, 150-154. Rozen, P. (2004). Cancer of the gastrointestinal tract: early detection or early prevention. European Journal of Cancer Prevention, 13, 71-75. Suzuki, H., Gotoda, T., Sasako, M. & Saito, D. (2006). Detection of early gastric cancer: misunderstanding the role of mass screening. Gastric Cancer, 9, 315-319. Tan, K. Y. & Fielding, J. W. L. (2006). Early diagnosis of early gastric cancer. European Journal of Gastroenterology and Hepatology, 18, 821-829. The Health of Immigrants in New York City. 2006. A Report from the New York City Department of Health and Mental Hygiene. Fund for Public Health in New York, Inc. Read More