Association of serum creatinine variability and risk of 1-year mortality among patients with cancer

Creatinine variability has a close and reciprocal relationship with cancer risk. However, the role of creatinine variability on mortality among cancer patients remains unclear. Thus, the objective here is to fill this gap. We conducted a multi-center study including all patients with solid tumors admitted to eight hospitals in China between January 1, 2013, and December 31, 2019, on their primary admission. The variability of blood creatinine was evaluated by the standard deviation (SD) and coefficient of variation (CV) . All deaths and causes of death were identified from the Chinese National Center for Disease Control and Prevention (CDC) Surveillance Points System. Analyses were constructed by multiple Cox regression models. The study comprised a total of 41,911 cancer patients, of which 9,050 events were observed. Higher serum creatinine fluctuation was associated with an elevated risk of one-year mortality significantly, with a hazard ratio of 1.62 (95% confidence interval, 1.52-1.72; P <0.001) for the standard deviation of creatinine in quartile four compared with quartile one. Furthermore, the association persisted even though all creatinine was within the clinically normal range. The coefficient of variation of creatinine showed similar results. Higher serum creatinine fluctuation during hospital admission is associated with an elevated risk of one-year mortality among cancer patients, even if the fluctuation is within the clinically normal range.