Post on 03-Jan-2016
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Gastric CancerRemains the most common malignancy in Japan and China . It was the first-ranked malignancyin the United States in the 1930s to1940s, but it has rapidly declined in more recent decades
Gastric neoplasms are predominantlyMalignant , and nearly 90 to 95 % of cases are adenocarcinomas.Less frequently observed malignanciesInclude lymphomas, especially non-Hodgkin’s lymphoma, as well assarcomas, such as leiomyosarcoma.
ADENOCARCINOMA OF THE STOMACHADENOCARCINOMA OF THE STOMACH
Epidemiology:
There is great geographic variation inthe incidence of gastric cancer worldwide,strongly indicating that environmentalfactors influence the pathogenesis of gastric carcinogenesis
Gastric adenocarcinoma localized tothe distal stomach has declined,the incidence rate of proximal gastric,gastro- esophageal adenocarcinomashas been steadily increasing in the United States
Th
The incidence of gastric cancer is variable in different parts of the word .
In japan 75 to 100 new cases per 100,000 per year. other areas of high prevalence include chile and Scandinavia.
Epidemiologic studies of high-risk populations have also suggested that genotoxic agents such as N-nitroso compounds may play a role in gastrictumorigenesis. N-nitroso compoundscan be formed in the human stomachby nitrosation of ingested nitrates,which are common constituents of the diet.
Etiology:
Risk factors for the development of gastric adenocarcinoma can bedivided into environmental andgenetic factors as well as precursorconditions
Typically, gastric cancer occurs between ages 50 to 70 years andis uncommon before age 30 years.The rates are higher in males thanfemales by 2 to 1.
The achlorhydria associated with gastritis related toH. pylori,pernicious anemia, or other causes favors the growthof bacteria capable of convertingnitrates to nitrites.
In united states is 7 cases per 100,000 per yr . It is the 10 th most common cause of cancer in USA .
Increase in incidence of adnocarcinoma of the distal esophagus and cardia of the stomach.
Patients with familial adenomatous polyposis also have a risk approximately three time higher than that of the general population of developing gastric cancer.
( كننده مستعد (عوامل
Blood group antigens have also been associated with gastric cancer .
With the incidence highest in persons with blood type A and lowest in persons with blood type O.
مستعد ) عوامل(كننده
Etiology :
Dietary factor: Salted Smoked fish Pickled vegetables Well-cooked meats
Fruit and fiber have been found to be protective.Vit C is thought to protect against some of the mutagens present especially in smoked foods
Atrophic gastritis and gastriccancer share a number of commonenvironmental risk factors.It is likely that atrophic gastritis and intestinal metaplasia representintermediary steps to gastric cancer.
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Pernicious anemia
Peptic ulcer disease
Iron deficiency
N-nitroso compounds
H2 antagonists
مستعد ) عوامل(كننده
Aspirin Nonsteroidal anti-inflamatory Drugs
have been associated with
a decreased risk of gastric cancer.
( كننده مستعد (عوامل
بررسي توزيع فراواني در متغيرهاي دموگرافيك
بيماران مبتال به سرطان
)در 1374-1369 سال ( 5در استان اصفهان
شماره پژوهشي طرح1010
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در سرطان وفور نسبتزنان