A new explanation of 'Asian paradox'

Although Helicobacter pylori (H. pylori) has been classified as a class I (or definite) carcinogen by World Health Organization (WHO), the controversy as to why only a minority of infected patients develop gastric cancer still remains. Moreover, in Asian countries such as Indonesia, Japan, China, and Thailand, where the H. pylori infection rates are similar, there is a significant difference regarding the outcome of gastric cancer. That fact has been termed the "Asian paradox".

A research article to be published on October 21, 2009 in the World Journal of Gastroenterology addresses this question. A research, led by Murdani Abdullah, MD from Division of Gastroenterology, Department of Internal Medicine, University of Indonesia, was based on the old concept of a cascade of mucosal changes that develops from acute/chronic gastritis to gastric cancer as proposed by P. Correa. The difference in the pattern of H. pylori-associated gastritis may explain the difference in the incidence of gastric cancer between Indonesia and Japan. Previous studies have never evaluated the cascade of gastric mucosal changes prior to gastric cancer. In this research, the transformation of gastric mucosa that is induced by H. pylori infection prior to gastric cancer was investigated. The transformation was then compared between Indonesian and Japanese patients, the two countries that represent the "Asian paradox".

From 1998 to 1999, 42 Japanese patients at Yamanashi Medical University Hospital, Koufu and 125 Indonesian patients at Metropolitan Medical Centre Hospital, Jakarta were consecutively enrolled. From this research, it was seen that there was a significant difference in the grade and activity of gastric mucosal changes between Indonesian and Japanese H. pylori-positive patients. This finding suggests that there may be a different host response between Indonesian and Japanese people regarding H. pylori infection. The authors believe that lifestyle and genetic factors are considered to play a major role, in the meantime, their research may act as the initial step in explaining the "Asian paradox".

Reference: Abdullah M, Ohtsuka H, Rani AA, Sato T, Syam AF, Fujino MA. Helicobacter pylori infection and gastropathy: A comparison between Indonesian and Japanese patients. World J Gastroenterol 2009; 15(39): 4928-4931

http://www.wjgnet.com/1007-9327/15/4928.asp

Correspondence to: Murdani Abdullah, MD, Division of Gastroenterology, Department of Internal Medicine, Faculty of Medicine University of Indonesia, Cipto Mangunkusumo Hospital, Jalan Diponegoro No. 71, Jakarta 10430, Indonesia. murdani@cbn.net.id

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World Journal of Gastroenterology (WJG), a leading international journal in gastroenterology and hepatology, has established a reputation for publishing first class research on esophageal cancer, gastric cancer, liver cancer, viral hepatitis, colorectal cancer, and H. pylori infection and provides a forum for both clinicians and scientists. WJG has been indexed and abstracted in Current Contents/Clinical Medicine, Science Citation Index Expanded (also known as SciSearch) and Journal Citation Reports/Science Edition, Index Medicus, MEDLINE and PubMed, Chemical Abstracts, EMBASE/Excerpta Medica, Abstracts Journals, Nature Clinical Practice Gastroenterology and Hepatology, CAB Abstracts and Global Health. ISI JCR 2008 IF: 2.081. WJG is a weekly journal published by WJG Press. The publication dates are the 7th, 14th, 21st, and 28th day of every month. WJG is supported by The National Natural Science Foundation of China, No. 30224801 and No. 30424812, and was founded with the name of China National Journal of New Gastroenterology on October 1, 1995, and renamed WJG on January 25, 1998.