Abstract: ObjectiveTo investigate the value of bombesin(BN)as a biological marker of gastric cancer by studying the expression of BN in gastric cancer and premalignant lesion.MethodsImmunohistochemical and reverse transeription PCR(RT-PCR)were used to determine the expression and distribution of protein and mRNA of BN in gastric cancer cases and the controls.ResultsCompared with that of the control(0.125 9±0.0248),the patients with chronic superficial gastritis(0.1318±0.0371),and the patients with chronic atrophic gastritis(0.111 4±0.019 4) the BN expressions in patients with atypical hyperplasia(0.338 7±0.046 5) and gastric cancer(0.394 6±0.062 1)were significantly higher(P<0.05 for all)and the BN expression in gastric cancer patients was higher than in atypical hyperplasia patients.The expression of BN mRNA in the control(0.105 6±0.029 7),chronic superficial gastritis(0.110 0±0.037 1)and chronic atrophic gastritis(0.091 4±0.021 3)were lower than that of gastric mucosal atypical hyperplasia(0.301 7±0.062 5)(P<0.05)and the BN mRNA expression in gastric cancer patients(0.695 8±0.072 4)was higher than that of atypical hyperplasia patients(P<0.05),with significant differences between gastric cancer patients and contols,chronic superficial gastritis patients and chronic atrophic gastritis patients.ConclusionBN plays a catalytic role in the process of gastric carcinogenesis,which could be a predictor for different stages of gastric disease and carcinosenesis.