Correlation between c-erbB-2 and P-glycoprotein Expression in Esophageal Carcinoma

Objective: To investigate the correlation between c-erbB-2 and multidrug resistance (MDR) and its clinical significance. Methods: Immunohistochemistry stain was used to examine the expression of c-erbB-2 and flow cytometry was used to detect the expression of P-glycoprotein (P-gp) in samples from 46 patients with esophageal carcinoma. Results: The positive expression rate of c-erbB-2 was 26.1% (12/46) in the 46 cases of esophageal carcinoma, of which 4 cases being low expression and 8 cases mediumhigh expression. The positive expression rate of P-gp was 60.9% (28/46) in the 46 cases of esophageal carcinoma, of which 6 cases being low expression, 13 cases medium expression and 9 cases high expression. Comparing c-erbB-2 with P-gp expression in different lymph node metastasis statuses showed that there was significant difference (P<0.01) between P-gp expressions with lymph node metastasis (31.09%±5.33%) and without lymph node metastasis (8.04%±3.03%) when c-erbB-2 expression was positive. Comparing c-erbB-2 with P-gp expression in different TNM stages of esophageal carcinoma showed that there was significant difference (P<0.01) between P-gp expressions in III-IV stage (33.68%±5.51%)and in II stage patients (9.30%±2.78%) when c-erbB-2 expression was positive. The tumor's size and differentiation degree were not related to c-erbB-2 and P-gp expression. Conclusion: The high level of P-gp expression was related to the positive expression of c-erbB-2 with the lymph node metastasis in clinical III-IV stage patients of esophageal carcinoma, suggesting that the double positive might lead to a poor prognosis. However, when the c-erbB-2 expression was negative, the lymph node metastasis and clinical staging were not related to the P-gp expression in esophageal carcinoma patients.