Blood Free-Circulating DNA Testing of Methylated RUNX3 Is Useful for Diagnosing Early Gastric Cancer.

The main modalities for gastric cancer screening are limited to upper gastrointestinal endoscopy and contrast radiography. The former is invasive, and the latter has high false-negative rates. Thus, alternative diagnostic strategies are required. One solution may be a liquid biopsy. Methylated RUNX3 is a well-known biomarker of gastric cancer but it is very difficult to detect with conventional bisulfite-based methylation assays when only a small amount of serum is available. We developed the combined restriction digital PCR (CORD) assay, a new methylation assay allowing for the counting of as little as one copy of a methylated gene in a small sample of DNA without necessitating DNA bisulfite treatment. We evaluated the sensitivity and specificity of the serum DNA testing of methylated RUNX3 by the CORD assay for the detection of early gastric cancer using 50 patients with early gastric cancer and 61 control individuals. The CORD assay had a sensitivity of 50.0% and a specificity of 80.3% for early gastric cancer. Methylated RUNX3 copies were significantly associated with tumor size, massive submucosal invasion, and lymph-vascular invasion. After the treatment, the median number of methylated RUNX3 copies was significantly decreased. The CORD assay may provide an alternative screening strategy to detect even early-stage gastric cancer.

Estimation of salt intake from spot urine may assist the risk assessment of gastric cancer.

Daily salt intake can be estimated by measuring sodium and creatinine concentrations in spot urine. Excessive salt intake is risk factor for gastric cancer. We examined the correlation between estimated salt intake from spot urine and risk of gastric cancer. This study included gastric cancer patients who underwent treatment at our hospital and patients in whom esophagogastroduodenoscopy was performed but gastric cancer was not observed. The history of H. pylori infection was known in these patients. Spot urine was collected, and daily salt intake was estimated from urine sodium and urine creatinine. Mean estimated salt intake was significantly higher in 120 gastric cancer patients (9.18 g/day) than in 80 non-gastric cancer patients (8.22 g/day). Multivariate analysis revealed estimated salt intake and H. pylori infection to be independent risk factors for gastric cancer. Among H. pylori-infected patients, salt intake was significantly higher in gastric cancer patients (9.25 g/day) than in non-gastric cancer patients (8.01 g/day). In conclusion, salt intake estimated from spot urine was high in patients with gastric cancer, especially in H. pylori infected patients. Spot urine is a simple examination and it may be applied as a new risk assessment of gastric cancer.

Lymph node metastasis can be determined by just tumor depth and lymphovascular invasion in early gastric cancer patients after endoscopic submucosal dissection.

PURPOSE: Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastric cancer (EGC) with negligible risk of lymph node metastasis (LNM). When a patient is determined to have noncurative resection after ESD, additional surgical resection with lymph node dissection is recommended. Previous studies report that LNM is found in about 10% of these patients. It may be possible to avoid unnecessary surgical resection by selecting patients properly. We aimed to clarify the risk factors associated with LNM in EGC patients who underwent ESD and to develop a highly accurate diagnostic algorithm for LNM. PATIENTS AND METHODS: Among 1005 patients with EGC who underwent ESD, 423 patients who could be followed up for more than 3 years after treatment or who underwent additional surgical resection were examined. We used the leave-one-out method to explore the combination of predictive factors of LNM and differentiated LNM by a unique classifier. RESULTS: Curative resection was achieved in 322 patients, whereas noncurative resection was achieved in 101 patients. In the noncurative resection group, LNM occurred in eight patients with additional surgical resection and one patient during follow-up. The combination of depth of invasion, lymphatic, and venous invasion showed the highest diagnostic performance and could differentiate LNM with 100% sensitivity, 86% specificity, and 86% diagnostic accuracy. CONCLUSION: More than 500 µm submucosal invasion and lymphatic and venous invasion will be useful in assessing LNM after ESD for patients with EGC. When these three factors are not observed, follow-up alone might be appropriate and it may be possible to reduce unnecessary surgical resection.