Safety of angiotensin converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) in patients with bladder and upper tract malignancies undergoing platinum-based chemotherapy: A retrospective study.

e16563 Background: ACEis and ARBs are commonly used in the management of hypertension and cardiovascular disease, but little is known about their safety and impact on renal clearance when used in patients with bladder and upper tract malignancies receiving platinum-based chemotherapy (PBC). Methods: We performed an IRB-approved retrospective analysis of patients with bladder and upper tract malignancies at the University of California, Irvine, who received PBC between November 2017 and July 2023. Patients were grouped into cohort 1 (PBC + ACEis/ARBs) and cohort 2 (PBC without ACEis/ARBs). We used Chi-square tests for categorical variables and Student’s t-tests for continuous variables, with logistic regression to identify independent risk factors. Results: A total of 145 patients (mean age: 70) were included, with 47/145 (32%) receiving ACEis/ARBs at chemotherapy initiation. 64/145 (44%) were treated for metastatic disease and 11/145 (7.6%) received chemoradiation. Cisplatin was given to 84/145 (57.9%), carboplatin to 58/145 (40%). While chemotherapy regimen modifications (dose reductions, delays, cessations) were more frequent in cohort 1, the difference was not statistically significant (66% vs. 51%, P = 0.09). Independent risk factors associated with any regimen alterations included older age (in years) (aOR, 1.06; 95% CI, 1.02 to 1.10; P = 0.001) and receipt of carboplatin (aOR, 2.11; 95% CI, 1.01 to 4.40; P = 0.046). Chemotherapy-induced cytopenia was found in 32/47 (68.1%) of patients in cohort 1 vs. (56/98) 57.1% of patients in cohort 2, P = 0.21). No significant differences in acute kidney injury (P = 0.57) or hospitalization rates (P = 0.18) were observed. In multivariable logistic regression analysis, older age (aOR, 1.09; 95% CI, 1.05 to 1.14; P < 0.001) and metastatic disease (aOR, 2.41; 95% CI, 1.08 to 5.35; P = 0.031) were associated with any cytopenia or AKI. Conclusions: Concurrent use of ACEis/ARBs in bladder and upper tract cancer patients receiving PBC was associated with trends toward higher chemotherapy-induced toxicities and treatment alterations, though these findings were not statistically significant. Older age and metastatic disease were associated with cytopenias or AKI. These trends are worth exploring further in larger studies to ensure patient safety and treatment efficacy.