Comparative epidemiology of gastric cancer between Japan and China

AIM:To clarify the similarities and differences in gastric cancer epidemiology between Japan and China.METHODS:A comprehensive literature search of the PubMed database was performed.The relevant literature published in China was also been cited.Data on incidence and mortality rates in 2008 were obtained from the Cancer Mondial database,published by International Agency for Research on Cancer at http://www-dep.iarc.fr/.RESULTS:Gastric cancer remains a significant publichealth burden in both Japan and China.The prevalence of Helicobacter pylori(H.pylori)colonization is high in the adult populations of both countries.Accumulating evidence from intervention studies in both countries has shown the effectiveness of H.pylori eradication in reduc-ing gastric cancer incidence.There are differences,however,in many aspects of gastric cancer,including patterns of incidence and mortality,trends in the prevalence of H.pylori infection,H.pylori strains,the magnitude of risk of gastric cancer related to H.pylori infection,and associations with dietary habits.Compared with China,Japan has seen a more rapid decline in H.pylori infection among adolescents.While Japanese cohort studies have dominated the literature concerning the associations between gastric cancer and dietary habits,numerous case-control studies in China suggest a positive association between a high intake of preserved fish and vegetables and gastric cancer risk.There is a need for a multidisciplinary research approach to understand the interactions between various strains of H.pylori,host factors,and other lifestyle and environmental factors in gastric carcinogenesis in both countries.CONCLUSION:The shared high incidence of gastric cancer and high prevalence of H.pylori,as well as differences in many aspects of gastric cancer,provide an excellent opportunity to establish Sino-Japanese collaborations.

Increased tumor necrosis factor receptor 1 expression in human colorectal adenomas

AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-α and its receptors in 62 colorectal adenoma patients and 34 healthy controls. The protein expression of TNF-α, TNF-R1, TNF-R2 and downstream signals of the TNF receptors, such as c-Jun N-terminal kinase (JNK), nuclear factor-κ B and caspase-3, were also investigated in human colorectal adenomas and in normal colorectal mucosal tissues by immunohistochemistry. Immunofluorescence confocal microscopy was used to investigate the consistency of expression of TNF-R1 and phospho-JNK (p-JNK). RESULTS: The serum levels of soluble TNF-R1 (sTNF-R1) in adenoma patients were significantly higher than in the control group (3.67 ± 0.86 ng/mL vs 1.57 ± 0.72 ng/mL, P < 0.001). Receiver operating characteristic analysis revealed the high diagnostic sensitivity of TNF-R1 measurements (AUC was 0.928) for the diagnosis of adenoma, and the best cut-off level of TNF-R1 was 2.08 ng/mL, with a sensitivity of 93.4% and a specificity of 82.4%. There were no significant differences in the serum levels of TNF-α or sTNF-R2 between the two groups. Immunohistochemistry showed high levels of TNF-R1 and p-JNK expression in the epithelial cells of adenomas. Furthermore, a high incidence of co-localization of TNF-R1 and p-JNK was identified in adenoma tissue. CONCLUSION: TNF-R1 may be a promising biomarker of colorectal adenoma, and it may also play an important role in the very early stages of colorectal carcinogenesis.