Observational Analysis Of The Effect Of COX-2 Expression On The Efficacy Of Bevacizumab Treatment In Advanced Or Recurrent Colorectal Cancer

Objective:To explore the effect of COX-2 expression on the efficacy of first-line chemotherapy combined with bevacizumab in patients with advanced colorectal cancer and postoperative recurrent and metastatic colorectal cancer,by comparing the expression of COX-2 in colorectal cancer tissues of patients with advanced colorectal cancer and postoperative recurrent and metastatic colorectal cancer.Methods:This study retrospectively collected the clinical medical records of 50 patients with initial treatment of advanced or postoperative recurrence and metastasis of colorectal cancer who were admitted to the Department of Oncology and Gastrointestinal Surgery of the First Affiliated Hospital of Gannan Medical University from January 2017 to August 2022.Through the clinical electronic medical record system,imaging reading and follow-up,The clinical baseline data and progression-free survival(PFS)of all patients were obtained,and excel was used to record the baseline data for statistical analysis.Kaplan-Meier method and Log-rank test were used for univariate survival analysis between groups,and survival curves were drawn.The pathological tissue sections obtained by pathology department were subjected to COX-2 immunohistochemical staining to obtain the COX-2 expression staining of the above 50 patients,and the COX-2 staining was divided into COX-2(-),COX-2(+),COX-2(++),COX-2(+++)four groups according to the semi-quantitative integral method.Kaplan-Meier method and Log-rank test were used to compare the survival between the COX-2 positive group and the COX-2 negative group,and the survival curve was drawn.Furthermore,COX proportional hazards regression model was used to test all single factors including COX-2 expression.Finally,according to the literature,COX-2(-)and COX-2(+)in COX-2expression were combined as COX-2 low expression group.COX-2(++)and COX-2(+++)were used as the COX-2 overexpression group.Kaplan-Meier method and Log-rank test were used for analysis and comparison,and the survival analysis map was drawn.For all the above statistical steps,P < 0.05 was considered statistically significant.A P value of less than 0.01 was considered to indicate statistical significance.Results:A total of 50 cases were included in this study,and the results were recorded in excel.First,the survival curve of all cases was drawn by SPSS26.0 software,and the results showed that the median progression-free survival(PFS)was 6.9 months.The univariate analysis(gender,age,combined chemotherapy regimen,type of case,lung metastasis,RAS gene,tumor location,liver metastasis and COX-2 expression)between the two groups was compared by Kaplan-Meier method,and the results showed that: In the expression of COX-2,there were 14 cases of COX-2 negative expression(28.0%,median PFS 12.5 months)and 36 cases of COX-2 positive expression(72.0%,median PFS 6.3months).There was also a significant statistical difference between the two groups(P=0.004).In this study,COX-2 expression is correlated with the efficacy and prognosis of bevacizumab therapy in metastatic colorectal cancer,while gender,age,combined chemotherapy regimen,type of case,lung metastasis,RAS gene,tumor location,and liver metastasis are not correlated with the efficacy and prognosis of bevacizumab therapy in metastatic colorectal cancer.Cox proportional hazards regression model was used for multivariate survival analysis,and the results showed that liver metastasis(P=0.027 OR=2.713 OR 95%CI:(1.123,6.557));The expression of COX-2(P < 0.01OR=4.750 OR 95%CI:(2.136,10.563)),indicating that liver metastasis and COX-2 expression are independent factors affecting the efficacy of bevacizumab in the treatment of metastatic colorectal cancer.The PFS of patients without liver metastasis is better than that of patients with liver metastasis,and the PFS of patients with negative COX-2 expression is better than that of patients with positive COX-2 expression.The COX-2 subgroup was further stratified.According to the results of immunohistochemical staining,they were divided into COX-2 low expression group(-～ +)and COX overexpression group(++ ～ +++),and the results showed that: There was a significant difference in PFS between the COX-2 low expression group and the COX-2 high expression group(P < 0.01).The results showed that the difference in COX-2 expression could affect the efficacy of bevacizumab in the treatment of metastatic colorectal cancer.Based on the univariate analysis results,there was no significant difference between the combined chemotherapy regimens,further indicating that the higher the expression of COX-2 in colorectal cancer tissues,the higher the expression of COX-2 in colorectal cancer tissues.The efficacy of bevacizumab combined with chemotherapy in the treatment of advanced and postoperative recurrent and metastatic colorectal cancer is poor,which is basically consistent with the results speculated from the literature.Conclusion:(1)The expression of COX-2 in the tumor tissues of newly treated advanced colorectal cancer is different from that of postoperative recurrent and metastatic colorectal cancer.(2)The difference of COX-2 expression is an independent factor affecting the efficacy of bevacizumab combined with chemotherapy in patients with metastatic colorectal cancer or postoperative recurrent colorectal cancer.(3)In colorectal cancer tissues,with the increase of COX-2 expression,the efficacy of bevacizumab combined with chemotherapy in the treatment of newly diagnosed advanced and postoperative recurrent and metastatic colorectal cancer is worse,which is an important reason for the efficacy of bevacizumab,and has nothing to do with the chemotherapy regimen used in combination.