Bachground/Aims: To further understand the relationship between the cagA gene and gastric cancer, the positive rates of the cagA gene in cancer and non-cancer tissues were investigated separately in patients with gastric cancer. Methods: The cagA gene...
Bachground/Aims: To further understand the relationship between the cagA gene and gastric cancer, the positive rates of the cagA gene in cancer and non-cancer tissues were investigated separately in patients with gastric cancer. Methods: The cagA gene was detected by PCR and the ureC gene was analyzed as a positive control for the presence of Helicobacter pylori. Each of two endoscopic biopsies were obtained from cancer and non-cancer tissues of 41 patients with gastric cancer. Results: 1) The positive rate of the cagA gene in cancer tissues was 29.3% (12/41), which was significantly lower than that in non-cancer tissues (63.4%). 2) Twelve (29.3%) out of 41 were positive for the cagA gene in both cancer and non-cancer tissues, 14 were positive in only non-cancer tissues, none were positive in only cancer tissues, and 15 (36.6%) were negative in both sites. 3) The ureC gene was negative in cancer tissue in 12 (85.7%) among 14 cases who were cagA gene negative in the cancer tissue but positive in the non-cancer tissue. 4) There was no difference in the positive rate of the cagA gene according to age, stage, site, and pathologic cell type. Conclusions: These findings indicate that the positive rate of the cagA gene in cancer tissue was lower than that in non-cancer tissues and this might be related to a low infection rate of H. pylori in cancer tissue rather than the presence of cagA negative H. pylori in cancer tissues.