RESUMEN
<p><b>BACKGROUND</b>To investigate the expression level and its clinical significance of the multi-drug resistance (MDR) associated protein in lung cancer specimens.</p><p><b>METHODS</b>The expression levels of Pgp, MRP, GST-π and TopoII of MDR associated protein were detected in 60 lung cancer samples and 30 paracancerous tissues by S-P immunohistochemistry method.</p><p><b>RESULTS</b>The positive rate of Pgp, MRP, GST-π and Topo II in the lung cancer tissues was 40.0% (24/60), 61.7% (37/60), 45.0% (27/60) and 81.7% (49/60) respectively, which was significantly higher than those in paracancerous tissues (P < 0.01). No significant correlation was observed among the expression of multi-drug resistance-related protein and TNM staging, pathological type, cell differention and lymph node metastasis status (P > 0.05).</p><p><b>CONCLUSIONS</b>Lung cancer has overexpression of multi-drug resistant-related genes during the oncogenesis. Combined detection of these genes may be useful for guiding the lung cancer chemotherapy.</p>