Background: Aside effect of anti-angiogenic agent treatment is proteinuria. Evaluation of the severity of adverse effects and the decision to discontinue treatment is based on the qualitative analysis of urinary proteins. However, a qualitative analysis result may not be indicative of the actual amounts of protein excreted. In this study, we evaluated the possibility of using the urine protein/creatinine ratio(UPCR), instead of a qualitative urine analysis, to monitor patients treated with antiangiogenic agents.
Methods: Urinalysis data of patients receiving anti-angiogenic agents-bevacizumab, ramucirumab, or aflibercept-were retrospectively analyzed from clinical records. Acorrelation between the urine protein content(qualitative and quantitative analyses)and continuity of anti-angiogenic agent treatment was evaluated.
Results: Atotal of 24 patients (age, 70.83±7.45 years)who received treatment for colorectal cancer(n=17), lung cancer(n=4), gastric cancer(n=2), and breast cancer(n=1)were included. One hundred and sixty-five urinalysis results were collected. Alinear correlation between the qualitative urinalysis results(1+to 3+)and UPCR(r=0.746, p<0.01)was obtained. In patients with a urine protein content of 2+(qualitative analysis), the UPCR was <2.0 for 25 patients and ≥2.0 but <3.5 for 4 patients. Similarly, in patients with a urine protein content of 3+, the UPCR was <2.0 for 3 patients and ≥2.0 but <3.5 for 1 patient. Seventeen patients with a urine protein content of 2+ and 3 patients with a urine protein content of 3+ discontinued treatment with anti-angiogenic agents before estimation of the UPCR could be performed. These figures were reduced to 4 patients and 2 patients, respectively, following UPCR assessment.
Conclusions: Switching the estimation of proteinuria from a qualitative analysis to UPCR might lead to better safety monitoring and prevent unnecessary discontinuation of anti-angio- genic agent treatment.