Abstract: Objective To analyze the diagnostic value of long noncoding RNAs (lncRNAs) in platelets in early screening of colon cancer (CC). Methods The GSE68086 and GSE183635 datasets, which contain platelet lncRNAs data from CC patients and healthy controls, were analyzed using the “limma” package in R. The intersection of the results was utilized to identify differentially expressed lncRNAs (DElncRNAs). The Wilcoxon rank sum test in R language was used to analyze the differential expression of DElncRNAs in CC tissues and normal control tissues. Quantitative real-time PCR (qRT-PCR) was used to detect the expression levels of platelet LINC00926 in 60 healthy controls and 66 CC patients. The receiver operating characteristic (ROC) was used to evaluate diagnostic performance. Results The differential analysis of GSE68086 dataset identified 341 DElncRNAs, and the GSE183635 dataset identified 21 DElncRNAs. The key DElncRNA LINC00926 was obtained from the intersection. R language Wilcoxon rank sum test showed that the expression level of platelet LINC00926 in CC tissues was lower than that in normal colon tissues (P<0.05). qRT-PCR confirmed that down-regulation of platelet LINC00926 in CC patients and early-stage CC patients (both P<0.001). The area under the curve (AUC) of platelet LINC00926 for CC diagnosis was 0.781, with a specificity of 80.0% and sensitivity of 74.2%. AUC for early-stage CC diagnosis was 0.761, with a specificity of 78.3% and sensitivity of 70.8%. The combined diagnostic model of platelet LINC00926 and carcinoembryonic antigen (CEA) had an AUC of 0.864, a specificity of 91.7% and sensitivity of 69.7%. The AUC for early-stage CC diagnosis was 0.851, with a specificity of 75.0% and sensitivity of 85.4% (P<0.05). In both CC and early-stage CC, the detection of AUC of platelet LINC00926 combined with CEA was superior to that of single detection (z =-2.619, 2.388, respectively, both P<0.05). Conclusion The LINC00926 expression in platelets of CC patients was down-regulated. It suggests that platelet LINC00926 may enhance the diagnostic value of early screening for colon cancer.

Key words: Colon cancer, Platelet lncRNA, Early screening