Amyloid Beta (A4) Precursor Protein: A Potential Biomarker for Recurrent Nasopharyngeal Carcinoma

Figures & data

Table 1 Clinical Characteristics of ELISA Samples

		nrNPC	rNPC	P value
Sex	Male(n)	17	27	>0.05
	Female(n)	5	2
Clinical stage	Low (I+II)(n)	4	4	>0.05
High (III+IV)(n)	18	25
Mean age±SD(y)		41.77±9.46	49.34±9.17	0.006

Note: Data are expressed as number(n) or year(y).

Abbreviations: nrNPC, nonrecurrent nasopharyngeal carcinoma; rNPC, recurrent nasopharyngeal carcinoma.

Figure 1 All identified protein name identifiers were searched against the STRING database version 9.1 for PPI. We found the high connective degree of APP (degree=34).

Figure 2 The cluster included 19 proteins (A2M, ACTN4, ALB, ALDOA, APP, CFD, F13A1, FN1, HRG, KNG1, PF4, PLG, PPBP, SERPINA1, SERPINE1, SERPING1, TIMP1, VWF) among which APP and SERPINE were up-regulated, the others were down-regulated.

Figure 3 APP significant difference between patients with rNPC compared to nrNPC in the levels of serum (P=0.008).

Figure 4 The area under the ROC curve was 0.666 (95% CI: 0.514–0.818, P = 0.044). The best cutoff point of the relative expression levels for APP was 1.23 (concentration = 16.95 ng/mL), at which the sensitivity was 55.2% and the specificity was 90.9%.