Acute kidney injury in cancer patients: A nationwide survey in China

Cancer patients have a high risk for acute kidney injury (AKI); however, the incidence, severity, and risk factors of malignancy-related AKI (MR-AKI) are unclear. This study aimed to assess MR-AKI risk factors and provide reliable data for AKI prevention, diagnosis, and management in China. This cross-sectional study analysed data from 44 academic and local hospitals in China. AKI patients were identified based on 2 screening criteria: the 2012 Kidney Disease: Improving Global Outcomes-AKI definition and the expanded screening criteria for patients with no repeated serum creatinine (SCr) test within 7 days and those who recovered from AKI. Patients whose SCr level increased or decreased by 50% during hospitalization, compared with that at admission, were considered to have AKI according to the expanded criteria. A total of 7,604 AKI patients were enrolled (1,418 with MR-AKI). Patient characteristics were compared between the MR-AKI and non-MR-AKI groups. Multivariate logistic models were used to statistically assess risk factors. The proportions of MR-AKI patients in academic and local hospitals were 20.2% and 14.1%, respectively. The incidence of MR-AKI was higher in mid-China (the affluent region), elderly patients, and groups with higher per capita gross domestic product. Among MR-AKI cases, gastrointestinal cancer (50.1%) was the most common malignancy, followed by cancers of the reproductive (15.3%), haematological (13.1%), respiratory (11.8%), and other systems (8.3%), and cancers of unknown classification (1.4%). Of 268 hospital deaths, respiratory, haematological, gastrointestinal, reproductive, other system, and unknown classification cancers accounted for 29.3%, 18.8%, 18.6%, 12.9%, 16.9%, and 20.0%, respectively. Increased age, advanced AKI stage at peak, level of per capita gross domestic product, geographic region, and renal replacement therapy indication were risk factors for hospital mortality in patients with gastrointestinal MR-AKI, whereas cardiovascular disease history, AKI stage at peak, and geographic region were risk factors for mortality in patients with reproductive MR-AKI. The incidence and mortality of MR-AKI vary by hospital, economic level, age, geographic region, and malignancy type. High MR-AKI incidence was associated with gastrointestinal cancers and higher level of medical care provided by academic hospitals in affluent regions such as Beijing, Shanghai, and other provincial-level cities. Elderly patients with advanced gastrointestinal cancer in mid-China showed the highest incidence of MR-AKI and in-hospital mortality, and thus require special attention.