The importance of urine protein-to-creatinine ratio in elderly patients receiving angiogenesis inhibitors

Abstract Background Patients receiving angiogenesis inhibitor treatment require attention regarding proteinuria. Monitoring proteinuria using the urine protein-to-creatinine ratio (UPCR) is critical. However, the utility of the UPCR for administering angiogenesis inhibitors to elderly patients remains unclear. Objectives We retrospectively examined whether UPCR measurements are associated with improved efficacy and safety of angiogenesis inhibitors in elderly patients. Methods This study included patients who experienced grade 2 or higher proteinuria at least once after the administration of angiogenesis inhibitors. The UPCR values at which bevacizumab and ramucirumab could be administered were defined to be less than 3.5 and 2.0, respectively. The actual total dose/planned total dose was used as an efficacy indicator. A proteinuria rate of grade 2 or higher was used as a safety indicator. Results There were 14 patients in both the UPCR and qualitative test groups. The medians of the actual total dose/planned total dose (%) for the angiogenesis inhibitors in the UPCR and qualitative test groups were 96.8 (48.5–103.9) and 77.7 (9.1–93.1), respectively, with that in the UPCR group being significantly higher (p  Conclusions Monitoring UPCR in elderly patients with grade 2 or higher proteinuria increases the total dosage of angiogenesis inhibitors, which may enhance their therapeutic effects. However, nephrotic syndrome was not fully confirmed in this small-scale study. Although further safety verifications are needed, our findings highlight the importance of monitoring UPCR to improve the efficacy and safety of angiogenesis inhibitors in elderly patients.