Serum long non-coding RNA signatures serve as novel noninvasive biomarkers for diagnosis and prognosis of gastric cancer

Gastric cancer (GC) is prevalent worldwide, and improvements in timely and effective diagnosis are imperatively needed. Recent advantages of cell free long non-coding RNAs (lncRNAs) open a new realm of possibilities for noninvasive diagnosis and prognosis of GC. The aim of this study was to identify potential lncRNA expression signatures for diagnosis of patients with GC along with prognostic prediction. We performed genome-wide serum lncRNA analysis by Hiseq sequencing followed by evaluations in the training and validation sets with reverse transcription quantitative real-time PCR assays from serum samples of 230 patients with GC and 230 controls. Four lncRNAs (XIST, LOC100506474, UCA1 and LINC00467) were identified to be significantly dysregulated in above serum samples, and a panel was finally developed by multivariate logistic regression model with an area under the receiver operating characteristic curve of 0.888 on validation cohort. The corresponding AUCs of the panel for patients with TNM stage I, II and III were 0.784, 0.851 and 0.931, respectively, significantly higher than that of CA19-9. Kaplan-Meier analysis showed that patients with high levels of XIST and LOC100506474 had worse recurrence-free survival (P=0.008 and 0.019, respectively). The multivariate Cox analysis demonstrated that XIST and LOC100506474 were both independently associated with tumor recurrence of GC (P=0.003 and 0.010, respectively). In conclusion, our study established a serum lncRNA panel with considerable clinical values in predicting and providing prognostic information for GC and identified XIST and LOC100506474 as potential biomarkers that can provide information on the recurrence risk of GC.