P-glycoprotein and topoisomerase II α expression in advanced gastric cancer patients: Association with clinicopathological findings
Comparative study of markers of drug resistance in cancer tissues may be extremely helpful in selection or effective chemotherapeutic regimen. P-glycoprotein (P-gp) and Topoisomerase II ? (Topo II ?) are two fundamental proteins in multi-drug resistance phenomenon (MDR). This study determined the expression and significance of P-gp and Topo II ? proteins in advanced gastric carcinomas and correlated molecular alterations with clinicopathological findings. Tissue samples of 35 patients with advanced type gastric adenocarcinoma were analyzed. Immunohistochemical techniques were applied using primary antibodies for P-gp or Topo II ? and LSAB2 detection kit (Dako-Denmark). Positive immunostaining for P-gp and Topo II ? were observed in 42.9% and 17.2% of tumor samples, respectively. Negative expressions of P-gp and Topoll were associated with sex (p = 0.035 and 0.0001) and histological grade (p = 0.021 and 0.0001), respectively. Unlike P-gp, an inverse relationship between Topo II ? expression and size of tumors (p = 0.012) and lymphatic invasion (p = 0.013) were observed. Considering the key role of positive P-gp or negative Topo II ? expression in MDR, it could be concluded that groups of patients with P-gp over expression (42.9%) or lack of Topo II ? expression (82.8%) would less likely benefit from available chemotherapeutic regimens. Therefore, we highly recommend determination of tumor status for expression of tumor markers such as P-gp and Topo II ?, before deciding about effective chemotherapeutic regimen for patients with gastric cancer. © 2006 Asian Network for Scientific Information.