Chemotherapy-Induced Hematological Toxicity in Patients with Renal or Hepatic Impairment

<b>Background/Objectives</b>: Hematological toxicities (i.e., neutropenia, thrombocytopenia, and anemia), are common chemotherapy complications and may be exacerbated by renal or hepatic impairment due to altered drug exposure. This study assessed the association between renal and hepatic impairment and hematologic toxicities during chemotherapy in routine clinical practice. <b>Methods</b>: A single-center retrospective cohort study using the Utrecht Patient Oriented Database (UPOD) identified all chemotherapy administrations at the University Medical Centre Utrecht between 2011 and 2024. Regimens administered in ≥10 patients and ≥5 renally (GFR < 60 mL/min) or hepatically (bilirubin or AST > 1× ULN) impaired patients were included in descriptive analyses. Cox proportional hazards models estimated associations between organ impairment and grade ≥ 3 hematologic toxicities for regimens with ≥10 events per toxicity endpoint. <b>Results</b>: Overall, 4489 patients were included in renal analyses and 6218 in hepatic analyses, with smaller endpoint-specific subgroups for survival analyses. Renal impairment was associated with grade ≥ 3 neutropenia (HR: 1.43 [95% CI: 1.18-1.73]), thrombocytopenia (HR: 1.46 [95% CI: 1.15-1.86], and anemia (HR: 1.66 [1.27-2.16]). Hepatic impairment was similarly associated with neutropenia (HR: 1.25 [95% CI: 1.11-1.40]), thrombocytopenia (HR: 1.33 [95% CI: 1.13-1.57]), and anemia (HR: 1.62 [95% CI: 1.34-1.95]). Cyclophosphamide (pro-drug) regimens showed higher toxicity risk in renally impaired patients and reduced risk in hepatically impaired patients. Etoposide, melphalan and methotrexate were associated with increased toxicity in hepatically impaired patients. <b>Conclusions</b>: Renal and hepatic impairment significantly increase chemotherapy-induced hematologic toxicity. Several high-risk chemotherapy regimens were identified; however, larger multi-center datasets are needed to refine dosing guidance based on renal and hepatic function.