The Clinical Diagnostic Value of Serum Cystatin C in Patients with Prostate Cancer

Objective To investigate the value of serum cystatin C (Cys-C) in the clinical diagnosis of prostate cancer patients (PCa). Methods We utilized data from the 2001-2002 National Health and Nutrition Examination Survey (NHANES) cycle. Variables were downscaled by LASSO regression to screen for influencing factors, and parallel multifactorial cox regression analyses were performed to assess the association between Cys-C and prostate cancer, as well as restricted cubic spline (RCS) analyses. Subgroup analyses by age, education, race, body mass index, and smoking history were also performed. The correlation between age and Cys-C was analyzed using Spearman's correlation analysis. Results Mean ± standard deviation (SD) Cystatin C levels were higher than normal in prostate patients. The ratios (95% confidence intervals) of the univariate and multivariate models I, II and III were 1.6117 (0.0412,0.9144), 1.5841 (-0.0192,0.8819), and 1.3357 (-0.3876,0.8454), respectively. Restricted cubic spline regression analysis did not show a nonlinear correlation between cystatin C and PCa (nonlinear p=0.007). Spearman's correlation analysis showed that serum cystatin C levels were statistically significantly correlated with age (r=0.476,P<0.01). Kaplan⁃Meier survival curves showed that patients with high levels of Cystatin C had a faster downward trend in the survival curves. Elevated Cys-C was significantly associated with an increased risk of PCa, and prostate cancer patients with elevated Cys-C had a shorter time to survival and a lower survival rate. Conclusion Cys-C is positively correlated with the presence of PCa, serum Cys-C level has significant correlation with age, and Cys-C should be given clinically can be used as an auxiliary diagnostic index for regular monitoring of prostate cancer patients of different ages and normal people.