低肌酐/半胱氨酸-C（Cr/Cys-C）比值可能是低肌肉质量的生物标志物。此外，低Cr/Cys-C与总体生存期（OS）减少有关，但至今未在肾癌患者中进行研究。我们的目标是评估接受肾切除术治疗的肾癌患者的低Cr/Cys-C比值与OS和无复发生存期（RFS）之间的关联。我们对接受肾切除术治疗的肾癌患者进行了回顾性研究。排除了终末期肾病患者和随访时间不到1年的患者。将Cr/Cys-C按照队列的中位数二分（低 vs. 高）。使用Kaplan-Meier方法估计高Cr/Cys-C与低Cr/Cys-C患者的OS和RFS，并使用Cox比例风险模型建立与感兴趣结果的关联。使用相关性和Logistic回归评估Cr/Cys-C与骨骼肌质量之间的关联。共分析了255名患者，中位年龄为64岁。中位数（IQR）Cr/Cys-C为1（0.8-1.2）。低Cr/Cys-C与年龄、女性、东方合作肿瘤学小组表现状态≥1、TNM分期和肿瘤大小有关。Kaplan-Meier和Cox回归分析表明低Cr/Cys-C与OS（HR = 2.97，95%CI，1.12-7.90，P =0.029）和RFS（HR = 3.31，95%CI，1.26-8.66，P = .015）减少有关。此外，低Cr/Cys-C表明患者患有放射线肌肉萎缩的风险增加2-3倍。低Cr/Cys-C与肾癌患者的不良肿瘤学预后有关，并且在验证之后，可能作为接受肾切除术治疗的肾癌患者肌肉消瘦存在的血清生物标志物有用。© 作者2023年出版。牛津大学出版社发布。

Low creatinine to cystatin-C ratio (Cr/Cys-C) may be a biomarker for low-muscle mass. Furthermore, low Cr/Cys-C is associated with decreased overall survival (OS), but to date, has not been examined in patients with renal cell carcinoma (RCC). Our objective is to evaluate associations between low Cr/Cys-C ratio and OS and recurrence-free survival (RFS) in patients with RCC treated with nephrectomy.We performed a retrospective review of patients with RCC treated with nephrectomy. Patients with end-stage renal disease and less than 1-year follow up were excluded. Cr/Cys-C was dichotomized at the median for the cohort (low vs. high). OS and RFS for patients with high versus low Cr/Cys-C were estimated with the Kaplan-Meier method, and associations with the outcomes of interest were modeled using Cox proportional Hazards models. Associations between Cr/Cys-C and skeletal muscle mass were assessed with correlations and logistic regression.A total of 255 patients were analyzed, with a median age of 64. Median (IQR) Cr/Cys-C was 1 (0.8-1.2). Low Cr/Cys-C was associated with age, female sex, Eastern Cooperative Oncology Group Performance Status ≥1, TNM stage, and tumor size. Kaplan-Meier and Cox regression analysis demonstrated an association between low Cr/Cys-C and decreased OS (HR = 2.97, 95%CI, 1.12-7.90, P =0.029) and RFS (HR = 3.31, 95%CI, 1.26-8.66, P = .015). Furthermore, a low Cr/Cys-C indicated a 2-3 increase in risk of radiographic sarcopenia.Lower Cr/Cys-C is associated with inferior oncologic outcomes in RCC and, pending validation, may have utility as a serum biomarker for the presence of sarcopenia in patients with RCC treated with nephrectomy.© The Author(s) 2023. Published by Oxford University Press.