Expression Of GADD45A In Colorectal Cancer For Prediction Of Response To XELOX Neoadjuvant Chemotherapy

Objective:To explore the relationship between GADD45A protein expression and thecurative effect of XELOX neo-adjuvant chemotherapy in patients with colorectalcancer, finding related proteins which can sensitively predict the effect of XELOXregimen in neo-adjuvant chemotherapy of colorectal cancer. Further more, to provideclinical significance for patients with colorectal cancer who receive neo-adjuvantchemotherapy.Methods:Collect67patients with colorectal cancer who received3courses XELOXchemotherapy in the First Affiliated Hospital of Nanchang University. These patientsall had pathological specimens of colonoscopy biopsy before chemotherapy andcancer tissues resected after surgery,30pathological specimens which were10cmaway from primary tumor were confirmed as normal colorectal mucosa. Then detectthe expression of protein GADD45A in cancer tissue and normal colorectal mucosausing EnVision immunohistochemistry method. Thus to assess the efficacy ofXELOX chemotherapy regimen according to the expression of GADD45A in patientswith colorectal cancer.Results：1. GADD45A positive expression rate in colorectal cancer tissue was47.8percent (32/67) and it was73.3percent (22/30) in normal mucosal tissue，GADD45Aexpression in colorectal cancer tissues was significantly lower than normal colorectalmucosa with P＜0.05,which showed a statistically significant difference；2.GADD45A positive expression rate in colorectal cancer tissue before XELOXneo-adjuvant chemotherapy was47.8percent(32/67) and it was58.2percent(39/67)in colorectal cancer tissue resected by surgery after XELOX chemotherapy,GADD45A expression in colorectal cancer tissues before neo-adjuvant chemotherapywas significantly lower than the rate after neo-adjuvant chemotherapy，P＞0.05, which had no significant；3. In XELOX chemotherapy regimen，GADD45A positiveexpression rate was70.7percent (29/41) in the effective group namely the diseasecontrol group（CR+PR+SD）；GADD45A positive expression rate was percent38.5（10/26）in the invalid group namely the tumor progression group（PD）；the proteinGADD45A positive expression rate was significant higher in disease control group（CR+PR+SD） than tumor progression group（PD），P＜0.05,which had astatistically significant difference;4, The relationship between GADD45A andtumor differentiation degree of patients with colorectal cancer：the rate of GADD45Apositive expression in well differentiated group was75%(12/16), which was55.6%(10/18) in moderately differentiated group，and30.3%(10/33) in poorly differentiatedgroup, p <0.05, the percentage of GADD45A contained in well，moderately，poorlydifferentiated group is in a decreasing manner and had significant differences;5.Therewas no significant difference of GADD45A positive expression in gender、age、pathological stage and lymph node metastasis，P＞0.05，which had no significantdifference.Conclusions:GADD45A positive expression rate in colorectal cancer tissue was lower thanthat in normal mucosal tissue; And the XELOX chemotherapeutic effect analysiswere as follows: the GADD45A positive expression rate in disease control group(CR+PR+SD) was higher than that in tumor progression group (PD); GADD45Aexpression in resected tumor tissues of patients with colorectal cancer who receiveXELOX neo-adjuvant chemotherapy was significantly higher than that in colorectalcancer tissues before neo-adjuvant chemotherapy.Experimental results showed that，we could assess the efficacy of XELOX chemotherapy regimen according to theGADD45A expressed pre and post chemotherapy in patients with colorectal cancerand provide clinical significance for neo-adjuvant chemotherapy in colorectal cancer.