Clinical Efficacy Of Bevacizumab Combined With Chemotherapy In The Treatment Of Metastatic Colorectal Cancer

Objective:Through the clinical study of bevacizumab combined with chemotherapy in the treatment of metastatic colorectal cancer,the present clinical research status,treatment effect,influencing factors and treatment safety of bevacizumab were discussed.Methods:In this paper,observational study method was adopted to collect relevant clinical data of 91 patients with metastatic colorectal cancer who received bevacizumab combined with chemotherapy in the People's Hospital of Zhengzhou University from July 2016 to August 2019,and systematic statistics and analysis were conducted.Among them,34 patients were treated with oxaliplatin-based chemotherapy regimens(CapeOx,mFOLFOX6 or FOLFOX4),48 patients were treated with irinotecan-based chemotherapy regimens(FOLFIRI),and 9 patients were treated with single-agent therapy(fluorouracil,capecitabine or raltitrexed).In this study,medical histories of the patients were recorded,and routine examination data such as blood,urine,stool and electrocardiogram were collected in the first week before treatment,and imaging examination results of chest,abdomen and basin were collected in the fourth week before treatment.In addition,biochemical and imaging examinations were performed on the patients every 6 to 8 weeks as the basis for the regular evaluation of efficacy and related adverse reactions.This study analyzes the efficacy and safety of bevacizumab combined with chemotherapy in 91 patients.Based on the hierarchical analysis,this study compares the different gender,age,ECOG PS score,primary tumor site,tumor stages at the first visit,the chemotherapy regimens administered,whether the risk of high blood pressure,whether partial treatment was effective or not,whether the primary lesion was resected or not,the number of organs with metastases,the existence of ascites,whether adjuvant chemotherapy affected between two groups.The prognostic factors of bevacizumab combined with chemotherapy for metastatic colorectal cancer are analyzed by multivariate analysis.In this study,SPSS 22 statistical software package is used to analyze and process the collected data.Results:A total of 91 patients meeting the criteria were included in this study.46 of the patients were male and 45 were female,and the patients were aged 20-74 years with an average age of 56 years.The median follow-up duration was 17.4 months(6-33.4 months).Of all the patients,11 patients continued treated after this date,but 80 patients had stopped using bevacizumab for various reasons,and 21 patients had disease progression.The median duration of all 91 patients treated with bevacizumab was 3.4 months(0.5-16.5 months),Among them,42 patients received first-line treatment,36 patients received second-line treatment,and 13 patients received third-or-fourth-line treatments.The total objective response rate(ORR)for all patients was 43.9%and the disease control rate(DCR)was 87.8%.The median PFS of all patients was 6.4 months(95%CI,5.0-7.8 months)and the median OS was 20.2 months(95%CI,16.3-24.1 months).For patients receiving first-line or second-line treatment,the ORR was 24%and 11%,the DCR was 37%and 27%,the median PFS was 8.6 and 5.5 months,and the median OS was 21.9 and 17.1 months,respectively.For patients receiving third-line or fourth-line treatment,the ORR was 1%,the DCR was 8%,and the median PFS was 3.6 months,but the median OS had not been reached.Among them,the median PFS of first-line treatment,second-line treatment,third-line and fourth-line treatments were different and the difference was significant(P<0.05).First-line treatment was better than second-line treatment,third-line or fourth-line treatment(P<0.05).Stratified analysis showed that there was no significant difference in PFS and OS between gender,age,primary tumor site,tumor stages,the chemotherapy regimens administered,hypertension,whether combined local treatment and whether administered adjuvant chemotherapy(P>0.05).The PFS was closely related to the mode of treatments and the number of metastatic organs.The PFS of the group treated with chemotherapy regimens after bevacizumab was discontinued was longer than that of the group not treated with chemotherapy after bevacizumab was discontinued.The difference was significant(P<0.05).The PFS of the group with the number of metastatic organs?2 was shorter than that of the group with the number of metastatic organs<2,and the difference was significant(P<0.05).The.OS was closely related to whether the primary lesion was resected and the presence of ascites.The OS of the primary lesion resected group was longer than that of the primary lesion unresected group,and the difference was significant(P<0.05).The OS of the group with ascites was shorter than that of the group without ascites,and the difference was significant(P<0.05).In addition,PFS and OS in patients with metastatic colorectal cancer were significantly correlated with the ECOG PS score and whether chemotherapy was continued after discontinuation of bevacizumab.The PFS and OS of the group with lower ECOG PS score were significantly extended compared with the group with higher ECOG PS score(P<0.05).The PFS and OS were significantly extended in the group that continued chemotherapy following bevacizumab withdrawal(P<0.05).The incidence of adverse events related to bevacizumab was 51.6%.The main adverse events were hemorrhage(24.2%),hypertension(12.1%),proteinuria(6.6%),wound healing complications(4.4%),gastrointestinal perforation(2.2%),and thrombotic events(2.2%).Grade ? and grade ? adverse events included wound healing complications(4.4%),thrombotic events(2.2%),gastrointestinal perforation(1.1%),proteinuria(1.1%),and hypertension(1.1%).Most of the patients with adverse events were well tolerated after symptomatic treatment and did not affect treatment.Treatment was discontinued in 4 patients due to bevacizumab-related toxicities,including 1 case of ? hypertension,1 case of ? level gastrointestinal perforation,1 case of ? level gastrointestinal perforation and 1 case of ? level hematochezia.Bevacizumab therapy was suspended in 7 patients due to toxicities,including 4 cases with wound healing complications,1 case of ? proteinuria,1 case of left renal vein thrombosis and 1 case of right brachial vein thrombosis.In the rest of the 80 patients,there were 10 cases with grade 1 to grade 2 hypertension,5 cases with ?-? level proteinuria and 21 cases with ?-? hemorrhage.Conclusions:The results of this study indicate that bevacizumab combined with chemotherapy is effective in patients with metastatic colorectal cancer.The first-line treatment is more effective than the second-line and the third-or-fourth treatments.Multithreaded therapy can still achieve good objective remission rate and disease control rate.The shorter the duration of bevacizumab and chemotherapy,the worse the prognosis.The continuation of chemotherapy after bevacizumab was discontinuation,the number of metastatic organs<2,the resection of primary lesion,and the absence of ascites are good prognostic factors for the treatment of metastatic colorectal cancer with bevacizumab combined with chemotherapy.Although the incidence of total adverse events is high,most of them are grade ? and ? adverse events and chemotherapy-related adverse reactions.The adverse events related to bevacizumab are mainly hemorrhage,hypertension and proteinuria,but they are well tolerated.