Clinical significance of P-glycoprotein and topoisomerase II expression in gastric cancer

AIM: To investigate the correlation of P-glycoprotein (P-gp) and topoisomerase II (Topo II) protein expression with the clinicopathological characteristics of gastric cancer. METHODS: A total of 1 107 surgical specimens of gastric cancer were collected from patients treated at Fuzhou General Hospital of Nanjing Military Command from January 2006 to August 2009. The protein expression of P-gp and Topo II in 775 specimens from gastric cancer patients having complete clinical data was examined by immunohistochemistry. RESULTS: The overexpression rates of P-gp and Topo II proteins in patients with gastric cancer were 52.39% (406/775) and 58.45% (453/775), respectively. P-gp protein overexpression was associated with depth of invasion, TNM stage, and lymph node metastasis (all P < 0.05), but not with sex, age, tumor site, histotype, differentiation, and distant metastasis (all P > 0.05). Topo II protein overexpression was associated with age, tumor site, depth of invasion, histotype, differentiation, and lymph node metastasis (all P < 0.05), but not with sex, TNM stage and distant metastasis (all P > 0.05). CONCLUSION: Detection of P-gp and Topo II protein expression may be used to assess the malignant biological behavior and prognosis of gastric cancer and can therefore provide a theoretical basis for choice of chemotherapy drugs for gastric cancer.