Background: Bevacizumab-induced proteinuria is known to occur when vascular endothelial cell receptors are blocked, which leads to decreased protein filtration. Although several studies have analyzed the correlation between therapeutic effect of bevacizumab and proteinuria, no conclusion has been established. Methods: In this retrospective study, colorectal cancer patients who received bevacizumab and urinary protein check from January 2015 to December 2016, were included. The incidence of proteinuria and the grade according to Common Terminology Criteria for Adverse Events (CTCAE) 4.0 were evaluated after bevacizumab administration. The primary objective was to correlate proteinuria with overall response rate (ORR) and time to progression (TTP). Primary lesion, metastasized organs, surgery or radiation therapy, chemotherapy were investigated for analysis of risk factors for proteinuria development. Results: A total of 149 patients included in the analysis. Proteinuria occurred 19.5% (n=29) in the study patients; 20 in grade 1, 7 in grade 2, and 2 in grade 3. ORR was 55.2% in the proteinuria group and 51.7% in the non-proteinuria group. There was no difference between two groups (p=0.89). The TTP through the survival curve was similar in both groups (10 months, p=0.97). The risk of proteinuria was high in patients who had liver metastasis (p=0.02) and no surgery (p=0.01). Conclusions These result indicates that bevacizumab-induced proteinuria expression was not correlated with the therapeutic effect on patients with colorectal cancer. Further analysis is required to find out the correlation between proteinuria and therapeutic effects. The risk of proteinuria was increased from patients who had liver metastasis, and no surgery.

Background: Bevacizumab-induced proteinuria is known to occur when vascular endothelial cell receptors are blocked, which leads to decreased protein filtration. Although several studies have analyzed the correlation between therapeutic effect of bevacizumab and proteinuria, no conclusion has been established. Methods: In this retrospective study, colorectal cancer patients who received bevacizumab and urinary protein check from January 2015 to December 2016, were included. The incidence of proteinuria and the grade according to Common Terminology Criteria for Adverse Events (CTCAE) 4.0 were evaluated after bevacizumab administration. The primary objective was to correlate proteinuria with overall response rate (ORR) and time to progression (TTP). Primary lesion, metastasized organs, surgery or radiation therapy, chemotherapy were investigated for analysis of risk factors for proteinuria development. Results: A total of 149 patients included in the analysis. Proteinuria occurred 19.5% (n=29) in the study patients; 20 in grade 1, 7 in grade 2, and 2 in grade 3. ORR was 55.2% in the proteinuria group and 51.7% in the non-proteinuria group. There was no difference between two groups (p=0.89). The TTP through the survival curve was similar in both groups (10 months, p=0.97). The risk of proteinuria was high in patients who had liver metastasis (p=0.02) and no surgery (p=0.01). Conclusions These result indicates that bevacizumab-induced proteinuria expression was not correlated with the therapeutic effect on patients with colorectal cancer. Further analysis is required to find out the correlation between proteinuria and therapeutic effects. The risk of proteinuria was increased from patients who had liver metastasis, and no surgery.