Incidence, risk factors and mortality of acute kidney injury in solid malignancies: a retrospective cohort study

Background: Patients with solid malignancies are susceptible to acute kidney injury due to cancer, patient, and treatment-related factors, leading to interrupted oncologic care and worsened survival. We evaluated the incidence, risk factors, and mortality association of acute kidney injury in patients with newly diagnosed solid tumors. Methods: This single-center retrospective cohort study included 669 adults with newly diagnosed solid malignancies in 2017 and at least 6 months of follow-up. Demographic, clinical, oncologic, and renal variables were recorded. Acute kidney injury incidence was estimated using cumulative incidence functions with death as a competing event. Factors associated with acute kidney injury were assessed using Cox and Fine–Gray regression models. The association between acute kidney injury and all-cause mortality was evaluated using a time-dependent Cox model. Results: Among 669 patients, 131 (19.6%) developed AKI during follow-up. At 20, 40, and 60 months, cumulative AKI incidence reached 11.6%, 16.1%, and 18.9%, while mortality reached 22.0%, 30.4%, and 33.5%, respectively. Risk factors identified via multivariable analysis included male sex, diabetes mellitus, advanced-stage disease, poor performance status (ECOG score ≥ 2), cisplatin, anti-vascular endothelial growth factor therapy, and lower baseline estimated glomerular filtration rate and albumin. Male sex, poor performance status, cisplatin, and anti-vascular endothelial growth factor therapy remained significant in competing risk analysis. Acute kidney injury was significantly associated with mortality when modeled as a time-dependent covariate (HR 8.35, 95% CI 6.57–10.63; p < 0.001). Conclusions: Acute kidney injury is a common and clinically significant complication in patients with newly diagnosed solid tumors and is strongly associated with mortality. Early identification of high-risk patients and closer renal monitoring may improve renal and overall outcomes.