Expression Of MRP2in Colorectal Cancer For Prediction Of Response To XELOX Neoadjuvant Chemotherapy

Objective:To investigate the expression of MRP2in colorectal cancer with XELOXneoadjuvant chemotherapy treatment and to evaluate their relations with tumorchemosensitity. To find one index can predict the XELOX in colorectal cancerefficacy of neoadjuvant chemotherapy, which can provide clinical guidingsignificance for personalized neoadjuvant chemotherapy in the future.Material and method:The Immunohistological Envision method was used to detect the expressions ofMRP2in67cases colorectal carcinoma with before and after three cycle XELOXneoadjuvant chemotherapy,30cases adjacent normal colorectal mucosa.Analysis therelationship between MRP2enzyme activity and the curative effect of XELOXneoadjuvant chemotherapy in patients with colorectal carcinoma.Result:1、The expressions rate of MRP2protein in adjacent normal colorectal mucosa is13.3percent (4/26), in colorectal carcinoma tissue is46.3percent(31/67),the twogroups had significant difference(P<0.05),the expressions rate of MRP2in colorectalcarcinoma tissue is higher than that in normal mucosal tissue.2、During the XELOX neoadjuvant chemotherapy,MRP2positive expressionsrate in effective treatment group before neoadjuvant chemotherapy is21.9percent,MRP2positive expressions rate in ineffective treatment group is4.6percent.The effective rate of MRP2positive expression before neoadjuvantchemotherapy is29percent(9/31),that of MRP2negative expression beforeneoadjuvant chemotherapy is88.9percent(32/36),the two groups had significantdifference(P<0.05).The effective rate of MRP2negative expression beforeneoadjuvant chemotherapy is significantly higher than that of patient with MRP2positive expression.3、The MRP2positive expressions rate in well-differentiated group colorectal carcinoma tissue is18.8percent（3/16）, the MRP2positive expressions rate inmoderate-differentiated group colorectal carcinoma tissue is55.6percent（10/18）,theMRP2positive expressions rate in poor-differentiated group colorectal carcinomatissue is54.5percent（18/33）.The expressions of MRP2in moderately and poorlydifferentiated group were significantly higher than those in well-differentiatedgoup(P<0.05).4、The MRP2positive expressions rate in colorectal carcinoma tissue before andafter neoadjuvant chemotherapy is46.3percent and52.5percent,and there is nosignificant difference between them (P>0.05).5、The expression of MRP2is unrelatedto sex, age, colorectal carcinoma gross classification, pathological staging(each for P＞0.05).Conclusion:1、The expressions rate of MRP2in colorectal carcinoma tissue is higher thanthat in normal mucosal tissue.Besides，the expressions of MRP2in moderately andpoorly differentiated goup were significantly higher than those in well-differentiatedgroup.2、 The effective rate of MRP2negative expression before neoadjuvantchemotherapy is significantly higher than that of patient with MRP2positiveexpression,which suggests that we can take the expression of MRP2as one of theindex to predict the efficacy of neoadjuvant chemotherapy.3、The MRP2positive expressions rate in colorectal carcinoma tissue before andafter XELOX neoadjuvant chemotherapy，which suggests that multidrug resistance(MDR) mediated by MRP2is intrinsic resistance.