Diagnostic value of circN4BP2L2 in type I and type II epithelial ovarian cancer

Background CircN4BP2L2 was previously identified to be significantly decreased in epithelial ovarian cancer (EOC) and was associated with disease progression. The aim of this study was to evaluate the diagnostic value of plasma circN4BP2L2 using the unifying model of type I and type II EOC. Methods A total of 540 plasma samples were obtained from 180 EOC patients, 180 benign ovarian cyst patients, and 180 healthy volunteers. CircN4BP2L2 was assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cancer antigen 125 (CA125) and human epididymis protein 4 (HE4) were assessed using enzyme-linked immunosorbent assay (ELISA). Receiver operating curve (ROC), the area under the curve (AUC), sensitivity and specificity were estimated. Results Low level of circN4BP2L2 was associated with advanced tumor stage (p < 0.01) in type I EOC. Decreased circN4BP2L2 was associated with lymph node metastasis (LNM) (p = 0.04) in type II EOC. The expression level of circN4BP2L2 in type I was similar to that in type II. CircN4BP2L2 could significantly separate type I or type II from benign or normal cohort (p < 0.01). Early-stage type I or type II EOC vs. benign or normal cohort could also be distinguished by circN4BP2L2 (p < 0.01). Conclusion CircN4BP2L2 might serve as a promising diagnostic biomarker for both type I and type II EOC. The diagnostic safety for circN4BP2L2 in early-stage type I or type II EOC is also acceptable. Further large-scale well-designed studies are warranted to investigate whether circN4BP2L2 is specific for all histologic subgroups.

Automated summary

CircN4BP2L2 may serve as a promising diagnostic biomarker for both type I and type II EOC. It was associated with advanced tumor stage in type I EOC and lymph node metastasis in type II EOC. CircN4BP2L2 could significantly separate type I or type II from benign or normal cohort.