After the eradication therapy for Helicobactor pylori (HP) infection has been spread in Japan, the improvements of gastric diseases including the some types of gastritis or gastric cancer incidences due to the HP infections are reported. Atrophic and intestinal metaplasitic changes of stomach mucosa are risk for gastric carcinogenesis, but it is difficult to predict the cancer development. In this paper, pathological scores bases on the Sydney System for the inflammation, activity, atrophy and intestinal metaplasia in gastric mucosa were analyzed, and comparing with mRNA expression for IL-8, COX-2 in stomach mucosa with/without HP infections, and the mRNA expression levels were inspected for its usefulness as a biomarker for the prediction of gastric cancer in patients with HP infections or a secondary cancer in patients with the remnant stomach after gastrectomy. Biopsy specimens from 148 patients with a diagnosis of benign gastric diseases, from 102 patients with gastrectomy were obtained. Semi-quantitative Real-Time PCR was performed for the detection of IL-8, COX-2 mRNA and these expression levels were calculated by the ratio between each mRNA and GAPDH as an internal control. The scores for inflammation in stomach mucosa detected by Sydney System were strongly associated with the mRNA expression levels of the IL-8, and IL-8 and COX-2 expression levels were compared with (1) a part of upper corpus in whole stomach, (2) a part of the anastomosis after gastrectomy, and (3) a part of upper corpus in the remnant stomach with HP positive or negative patients. IL-8 levels were higher in (2): 0.70, (1): 0.46, (3): 0.10 with HP positive and (2): 0.18 with HP negative patients than those of (3): 0.009 and (1): 0.003 in HP negatives, and these results in COX-2 were almost same tendencies as those of IL-8. After the eradication therapy for HP infections, both IL-8 and COX-2 mRNA levels were markedly decreased within 6 months after the eradication, but inter-individual variations for COX-2 levels were shown in some patients with the whole stomach or with gastrectomy. Inflammation and activity in the stomach mucosa evaluated by Sydney System and IL-8 mRNA levels were improved after the eradication therapy, completely and for long periods, but there were inter-individual variations of COX-2 mRNA levels in stomach mucosa. IL-8 mRNA levels will be a good biomarker to reflect the inflammation in stomach mucosa, and COX-2 mRNA expression should be investigated for the extended period as a biomarker, which may predict the risk for carcinogenesis.

[Proc Amer Assoc Cancer Res, Volume 45, 2004]