Discovery and Validation of Salivary Extracellular RNA Biomarkers for Noninvasive Detection of Gastric Cancer.

BACKGROUND: Biomarkers are needed for noninvasive early detection of gastric cancer (GC). We investigated salivary extracellular RNA (exRNA) biomarkers as potential clinical evaluation tools for GC. METHODS: Unstimulated whole saliva samples were prospectively collected from 294 individuals (163 GC and 131 non-GC patients) who underwent endoscopic evaluation at the Samsung Medical Center in Korea. Salivary transcriptomes of 63 GC and 31 non-GC patients were profiled, and mRNA biomarker candidates were verified with reverse transcription quantitative real-time PCR (RT-qPCR). In parallel, microRNA (miRNA) biomarkers were profiled and verified with saliva samples from 10 GC and 10 non-GC patients. Candidate biomarkers were validated with RT-qPCR in an independent cohort of 100/100 saliva samples from GC and non-GC patients. Validated individual markers were configured into a best performance panel. RESULTS: We identified 30 mRNA and 15 miRNA candidates whose expression pattern associated with the presence of GC. Among them, 12 mRNA and 6 miRNA candidates were verified with the discovery cohort by RT-qPCR and further validated with the independent cohort (n = 200). The configured biomarker panel consisted of 3 mRNAs (SPINK7, PPL, and SEMA4B) and 2 miRNAs (MIR140-5p and MIR301a), which were all significantly down-regulated in the GC group, and yielded an area under the ROC curve (AUC) of 0.81 (95% CI, 0.72-0.89). When combined with demographic factors, the AUC of the biomarker panel reached 0.87 (95% CI, 0.80-0.93). CONCLUSIONS: We have discovered and validated a panel of salivary exRNA biomarkers with credible clinical performance for the detection of GC. Our study demonstrates the potential utility of salivary exRNA biomarkers in screening and risk assessment for GC.

Impact of previous gastric or colonic resection on polyethylene glycol bowel preparation for colonoscopy.

INTRODUCTION: Adequate bowel preparation is essential for successful completion of colonoscopy. This study examines whether previous bowel resection affects the quality of bowel preparation. METHODS: This study prospectively included patients who had gastric or colonic resection (bowel resection group, n = 92) and a control group (n = 92). All patients received 4 L polyethylene glycol (PEG) for bowel preparation. Quality of colonic preparation was assessed using the Aronchick scale (excellent, good, fair, or poor) and was categorized as satisfactory (excellent or good) or unsatisfactory (fair or poor). We analyzed whether previous gastric or colonic resection is associated with unsatisfactory preparation. RESULTS: Bowel preparation quality was significantly different between the resection group (0, 39.1, 43.5, and 17.4%, for excellent, good, fair, and poor) and control group (3.3, 53.3, 38.0, and 5.5% for excellent, good, fair, and poor, P = 0.011). Inadequate bowel preparation was significantly higher in the resection group than in the control group (60.9% vs. 43.5%, P = 0.018). Univariate analysis revealed height, weight, body mass index, and bowel resection to be predictors of unsatisfactory preparation. Multivariate analysis revealed bowel resection [odds ratio (OR) 2.12; 95% confidence interval (CI): 1.16-3.86] and obesity (body mass index ≥ 25 kg/m(2)) (OR 2.16; 95% CI: 1.13-4.12) to be independent predictors of unsatisfactory preparation. The prevalence of unsatisfactory and poor bowel preparation quality was 79.3 and 37.9% in obese patients with previous bowel resection. CONCLUSIONS: Previous bowel resection was an independent predictor of unsatisfactory PEG bowel preparation. More attention is needed for patients with previous bowel resection, especially for obese patients.

Efficacy and tolerability of split-dose magnesium citrate: low-volume (2 liters) polyethylene glycol vs. single- or split-dose polyethylene glycol bowel preparation for morning colonoscopy.

OBJECTIVES: Preparation regimens for morning colonoscopy are suboptimal. The aim of this study was to test the efficacy and tolerance of a split-dose magnesium citrate-low-volume (2 liters) polyethylene glycol (PEG) regimen for morning colonoscopy. METHODS: A total of 232 patients were randomly assigned to receive 4 liters PEG (day before procedure; group 1, n=79), 2 liters PEG (day before procedure) followed by another 2 liters PEG (day of procedure; group 2, n=80), or magnesium citrate (250 ml, day before procedure) followed by 2 liters PEG (day of procedure; group 3, n=73). The quality of bowel cleansing, tolerability, and adverse effects in group 3 were compared with those in groups 1 and 2. RESULTS: Satisfactory bowel preparation was more frequently reported for group 3 than for group 1 (75% vs. 51%, P=0.001) and was similar to that for group 2 (75% vs. 76%, P=0.896). A significantly greater proportion of patients in group 3 graded their overall satisfaction as satisfactory compared with group 1 (43% vs. 23%, P=0.010), and the proportion was similar to that in group 2 (43% vs. 35%, P=0.133). Patients in group 3 were more willing to repeat the same preparation regimen, if necessary, than those in group 1 (93% vs. 48%, P<0.001) or group 2 (93% vs. 62%, P<0.001). CONCLUSIONS: The split-dose magnesium citrate-low-volume (2 liters) PEG regimen was more efficient than and preferred to the conventional regimen of 4 liters of PEG, and it was equally efficient as, but, again, preferred to the split-dose (2+2 liters) regimen for morning colonoscopy.