Diagnostic value of procalcitonin, C-reactive protein in children suffering from malignant solid tumor with concurrent infection and in progression of tumor

Abstract

Objective To discuss the diagnostic value of serum procalcitonin (PCT) and C-reactive protein(CRP) in children suffering from malignant solid tumor with concurrent infection and in tumor progressing stage. Methods A total of 94 cases of malignant solid tumor at Department of Pediatrics, Beijing Tongren Hospital, Capital Medical University from March to August 2016, were collected and divided into 2 groups: infection group(n=17) and non-infection group (control group, n=77). Meanwhile, the control group were further divided into stable tumor group (n=48) and the advanced tumor group(n=29). All of the serum specimens were detected for PCT and CRP levels.PCT and CRP levels were compared and statistically analyzed among different groups.The median(four digit spacing) was used to describe the data. Results PCT level significantly increased in the infection group [0.67(1.35) μg/L] compared with that of the control group[0.09(0.08) μg/L], and the difference was statistically significant(Z=-6.371, P=0.000). CRP level significantly increased in the infection group[95.00(93.42) mg/L] compared with that of the control group[1.99(12.49) mg/L], and the difference was statistically significant(Z=-5.555, P=0.000). During diagnosing infection, the area under the receiver operating characteristic curve (ROC curve) of PCT was 0.995(95%CI: 0.987-1.000), and the area under the ROC curve of CRP was 0.932(95%CI: 0.876-0.988); when the cutoff value of PCT was 0.468 μg/L, the sensitivity was 76.5%, and the specificity was 100.0%; when the cutoff value of CRP was 10.17 mg/L, the sensitivity was 88.2%, and the specificity was 72.7%.Compared to stable tumor group, PCT level of advanced tumor group significantly increased[0.12(0.08) μg/L vs.0.07(0.06) μg/L], and the difference was statistically significant(Z=-2.886, P=0.004); CRP level of the advanced tumor group significantly increased[10.34(27.84)mg/L vs.1.02(2.12) mg/L], and the difference was statistically significant(Z=-4.862, P=0.000). During diagnosing tumor progression, the area under the ROC curve of PCT was 0.697(95%CI: 0.572-0.823), and the area under the ROC curve of CRP was 0.832(95%CI: 0.738-0.926); when the cutoff value of PCT was 0.094 μg/L, the sensitivity was 72.4%, and the specificity was 66.7%; when the cutoff value of CRP was 2.39 mg/L, the sensitivity was 72.4%, the specificity was 72.9%.Correlation analysis showed that the PCT and CRP levels were positively associated with tumor progression, and the correlation of CRP (r=0.558, P=0.000) was much higher than that of PCT(r=0.331, P=0.003). Conclusions Both serum PCT and CRP are effective indicators in diagnosing tumor with concurrent infection.PCT is better in diagnosing infection than CRP, and is less influenced by tumor.CRP is a better way to identify whether tumor was in progress than PCT.Joint detection of 2 indexes in identification of children suffering from malignant solid tumor with concurrent infection and in progress has practical value for the diagnosis and treatment. Key words: Child; Malignant solid tumor; Infection; Procalcitonin; C-reactive protein