Objective: To investigate the differential expressions of multidrug resistance protein 1 (MDR-1), ribonucleotide reductase M1(RRM-1), epidermal growth factor receptor(EGFR), excision repair cross-complementation group 1 (ERCC-1) in primary tumors and metastatic lymph nodes of patients with non-small cell lung cancer (NSCLC), and analyze the relationship between the differential expressions and pathological types of NSCLC. Methods The expressions of MDR-1, RRM-1, EGFR and ERCC-1 were detected by immunohistochemistry in primary tumors and metastatic lymph nodes of 46 cases NSCLC patients. Wilcoxon signed ranks test was used to compare the differences in the expressions of these four molecular markers in primary lesions and metastatic lymph nodes. Fisher's exact test was used to analyze the relationship between differential expressions and pathological types of NSCLC.
Results: The expressions of MDR-1, RRM-1, EGFR, ERCC-1 were observed in a variety of pathological types of NSCLC. The expression of ERCC-1 was significantly different between primary tumors and metastatic lymph nodes for lung adenocarcinoma (P=0.026). But the expressions of MDR-1, RRM-1, EGFR were not significantly different between primary tumors and metastatic lymph nodes for all pathological types of NSCLC (P>0.05). Conclusion The expression of MDR-1, RRM-1, EGFR, ERCC-1 of primary tumors and metastatic lymph nodes is found in all NSCLC. The expression of ERCC-1 is significantly different in primary tumors from in metastatic lymph nodes of lung adenocarcinoma.