We aimed to explore the correlation between P27 expression and Helicobacter pylori (H.pylori) infection in gastric cancer, so as to provide evidence for understanding the pathogenesis of gastric cancer caused by H.pylori infection.

A total of 82 samples of gastric cancer tissues and 56 samples of tumor-adjacent normal tissues collected from the gastrectomy were enrolled into this study. Then, 14C-Urease Breathing Test was carried out to evaluate the infection of H.pylori in gastric cancer tissues, the expression of P27 in the tissue samples was detected by the immunohistochemistry staining, and the correlation between the H.pylori infection and P27 expression in gastric cancer was analyzed. Of 82 gastric cancer patients, there were 53 patients with H.pylori infection (64.63%). Among the patients with highly or moderately differentiated gastric cancer, the expression of P27 was much higher than that of patients with poorly differentiated gastric cancer (P<0.01). Besides, comparison of the P27 expression between males and females, among different age groups, tumor sizes, TNM stages, tumor infiltration degrees or lymph node metastasis showed no significant differences (P>0.05). Analysis of the correlation revealed that P27 expression was negatively correlated with the infection of H.pylori (P<0.01). Multifactorial Logistics regression analysis indicated that tumor differentiation was a risk factor of P27 positive expression in gastric cancer tissues (P<0.01). In addition, P27 expression in the gastric cancer tissues was lower than that in the tumor-adjacent normal tissues (P<0.01). In gastric cancer patients, expression of P27 is correlated with H.pylori infection which, via downregulating P27, can cause the cancerization of gastric mucosa, and P27, for its role in the development and progression of gastric cancer, is a potential auxiliary indicator for clinical diagnosis whether gastric cancer is complicated with H.pylori infection. So, P27 is a key indicator for diagnosis, treatment and prognostic evaluation of disease in the advanced stage.