ETIOLOGY AND RISK FACTORS FOR GASTRIC CANCER - A TARGETED REVIEW
Adenocarcinomas represent approximately 95% of stomach cancers. Although its incidence has been steadily declining for the past decades, gastric cancer remains one of the most common malignancies and a leading cause of cancer death. About 1/12 cancer deaths is attributed to this disease, and more than one million new cases are diagnosed worldwide each year. Among the most relevant risk factors should be mentioned H. Pylori infection, chronic gastritis, achlorhydria, gastric adenomatous polyps or pernicious anemia. Besides, gastric cancer is most common in older men and there is a marked regional variability, thought to be attributable to genetics or environmental factors, especially diet. In Europe, the average 5-year survival rate is 26%, probably due to the unavailability of a screening program, as the number of cases is considered insufficient. In contrast, in Japan and Korea, where the large number of new cases imposed a screening program on each person at the age of 50, the 5-year survival rate is considerably higher.
 B. F, F. J, S. I, S. RL, T. LA, and J. A, “Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries,” CA. Cancer J. Clin., vol. 68, no. 6, pp. 394–424, Nov. 2018.
 R. P and B. A, “Epidemiology of gastric cancer: global trends, risk factors and prevention,” Prz. Gastroenterol., vol. 14, no. 1, pp. 26–38, 2019.
 P. Rawla and A. Barsouk, “Epidemiology of gastric cancer: Global trends, risk factors and prevention,” Przeglad Gastroenterologiczny, vol. 14, no. 1. Termedia Publishing House Ltd., pp. 26–38, 2019.
 M. Balakrishnan, R. George, A. Sharma, and D. Y. Graham, “Changing Trends in Stomach Cancer Throughout the World,” Current Gastroenterology Reports, vol. 19, no. 8. Current Medicine Group LLC 1, 01-Aug-2017.
 H. Sung et al., “Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries,” CA. Cancer J. Clin., vol. 71, no. 3, pp. 209–249, May 2021.
 R. Sitarz, M. Skierucha, and J. Mielko, “Gastric cancer : epidemiology , prevention , classification , and treatment,” pp. 239–248, 2018.
 K. P, I. F, A. S, F. ND, and K. F, “Gastric cancer: descriptive epidemiology, risk factors, screening, and prevention,” Cancer Epidemiol. Biomarkers Prev., vol. 23, no. 5, pp. 700–713, 2014.
 E. C. Smyth, M. Verheij, W. Allum, D. Cunningham, A. Cervantes, and & D. Arnold, “Gastric cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up † on behalf of the ESMO Guidelines Committee,” 2016.
 T. Yamada, D. H. Alpers, A. N. Kalloo, N. Kaplowitz, C. Owyang, and D. W. Powell, “Textbook of Gastroenterology.”
 M. MH and E.-O. EM, “Genetics of gastric cancer,” Nat. Rev. Gastroenterol. Hepatol., vol. 11, no. 11, pp. 664–674, Nov. 2014.
 P. WS et al., “Somatic mutations of the trefoil factor family 1 gene in gastric cancer,” Gastroenterology, vol. 119, no. 3, pp. 691–698, 2000.
 K. JH et al., “Occurrence of p53 gene abnormalities in gastric carcinoma tumors and cell lines,” J. Natl. Cancer Inst., vol. 83, no. 13, pp. 938–943, Jul. 1991.
 S. G, H. SC, N. A, H. YZ, M. MA, and F.-P. CM, “The molecular biology of esophageal and gastric cancer and their precursors: oncogenes, tumor suppressor genes, and growth factors,” Hum. Pathol., vol. 25, no. 10, pp. 968–981, 1994.
 F. RC et al., “Hereditary diffuse gastric cancer: updated consensus guidelines for clinical management and directions for future research,” J. Med. Genet., vol. 47, no. 7, pp. 436–444, 2010.
 A. M, S. R, A. LA, M. JP, and J. HJ, “Features of gastric cancer in hereditary non-polyposis colorectal cancer syndrome,” Int. J. cancer, vol. 74, no. 5, 1997.
 M. S et al., “Gastric cancer in individuals with Li-Fraumeni syndrome,” Genet. Med., vol. 13, no. 7, pp. 651–657, Jul. 2011.
 H. N et al., “Frequency and spectrum of cancers in the Peutz-Jeghers syndrome,” Clin. Cancer Res., vol. 12, no. 10, pp. 3209–3215, May 2006.
 D. L. Worthley et al., “Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS): A new autosomal dominant syndrome,” Gut, vol. 61, no. 5, pp. 774–779, May 2012.
 de V. AC, H. J, and K. EJ, “The detection, surveillance and treatment of premalignant gastric lesions related to Helicobacter pylori infection,” Helicobacter, vol. 12, no. 1, pp. 1–15, Feb. 2007.
 C. P, P. MB, and W. KT, “Pathology of gastric intestinal metaplasia: clinical implications,” Am. J. Gastroenterol., vol. 105, no. 3, pp. 493–498, 2010.