RESUMEN
BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is a drug-resistant tumor. The expression of a multidrug resistant gene, P-glycoprotein (P-gp) is a major mechanism of drug resistance. The aims of our study were, firstly, to observe the expression rate of P-gp in HCC tissue obtained by percutaneous fine needle aspiration (PCNA) from stage IV HCC patients; secondly to examine the association between P-gp and chemotherapeutic response; and finally to investigate the correlation between p53 protein expression and P-gp expression. Subjects and METHODS: We studied 29 cases of stage IV HCC treated by systemic chemotherapy. Expression of P-gp and p53 were evaluated by immunohistochemical staining of HCC tissue with human monoclonal antibody, JSB-1 (Anti P-gp) and DO-7 (Anti p53), respectively. We analyzed the results of immunohistochemical staining of HCC tissues of the patients in relation to chemotherapeutic response and other clinical characteristics. RESULTS: The expression rate of P-gp was 27.6%. Partial response to anti-cancer chemotherapy was observed in 16.7% of the patients. Although we could not see a statistically significant association between P-gp expression and chemotherapeutic response, none of the responsive patients showed P-gp expression. p53 protein expression was found in 45% of the patients. There was no significant correlation between p53 protein expression and P-gp expression. CONCLUSIONS: Although the number of our study subjects was small, chemotherapy- responsive patients didn't show P-gp expression. P-gp expression might be used as a predictor of response to potentially toxic anti-cancer chemotherapy in HCC patients. Further study is warranted to confirm our results.