Objective：To investigate the relationship between expressions of multidurg resistance associated factors and chemosensitivity of 5-fluorouracil（5-FU） in lymph node metastases(LNMs) of colon carcinoma.
Methods：The chemosensitivity to 5-FU was measured by MTT assay, and the expressions of P-gp, GST-π, p53, survivin, Bcl-2 and Bax were determined immunohistochemically in 48 paired primary tumor (PT) and LNMs of colon carcinoma.
Results：The inhibition rates of LNMs cells for 5-FU were higher than that of PT (P＜0.05). The expressions of P-gp and Bax were higher in LNMs than those in PT (both P＜0.05), and lower expression of Bcl-2 was found in LNMs (P＜0.05). There was statistically negative correlation between inhibition rates and expression of P-gp in PT (P＜0.05); Bcl-2 had negative correlation with inhibition rates for 5-FU in LNMs (P＜0.05), and positive correlativity was found between Bax and inhibition rates for 5-FU (P＜0.05).
Conclusions：The main factors that affect chemosensitivity to 5-FU in colon carcinoma in PT and in LNMs are different. Effective adjuvant chemotherapy after operation and reversion of multidrug resistance(MDR) of colon cancers depends on targeting the metastatic component of the disease.