Non-Invasive Early Molecular Detection of Gastric Cancers

Gastric cancer (GC) is a significant source of global cancer death with a high mortality rate, because the majority of patients with GC are diagnosed at a late stage, with limited therapeutic choices and poor outcomes. Therefore, development of minimally invasive or noninvasive biomarkers which are specific to GC is crucially needed. The latest advancements in the understanding of GC molecular landscapes and molecular biological methods have accelerated attempts to diagnose GC at an early stage. Body fluids, including peripheral blood, saliva, gastric juice/wash, urine, and others, can be a source of biomarkers, offering new methods for the early detection of GC. Liquid biopsy-based methods using circulating sources of cancer nucleic acids could also be considered as alternative strategies. Moreover, investigating gastric juices/washes could represent an alternative for the detection of GC via invasive biopsy. This review summarizes recently reported biomarkers based on DNA methylation, microRNA, long noncoding RNA, circular RNA, or extracellular vesicles (exosomes) for the detection of GC. Although the majority of studies have been conducted to detect these alterations in advanced-stage GC and only a few in population studies or early-stage GC, some biomarkers are potentially valuable for the development of novel approaches for an early noninvasive detection of GC

Prognostic Assessment after Local Resection for the Treatment of Small Carcinoma in Lower Rectum

Local resection of the lower rectum was performed for the treatment of malignant polypoid lesions in 22 patients. The clinical outcomes of the procedure are summarized as follows; 1. For Ila + Ile type malignant polyp, transanal wedge resection of the entire rectal wall or a transsacral tube resection of the rectum should be performed; as a minimal preventive measure against local recurrence. 2. Early invasive carcinoma (sm) has a metastatic potential on distant organs. 3. In the case of polypoid carcinoma invading the muscle layer (pm), local resection was conducted only in the patients with distant metastasis or with serious complications and in aged patients. 4. When postoperative histological examination reveals a mistake in operative strategy, the patient should be reoperated immediately

Updates in the Field of Submucosal Endoscopy

Submucosal endoscopy (third-space endoscopy) can be defined as an endoscopic procedure performed in the submucosal space. This procedure is novel and has been utilized for delivery to the submucosal space in a variety of gastrointestinal diseases, such as a tumor, achalasia, gastroparesis, and subepithelial tumors. The main submucosal endoscopy includes peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, and endoscopic submucosal tunnel dissection. Submucosal endoscopy has been used as a viable alternative to surgical techniques because it is minimally invasive in the treatment and diagnosis of gastrointestinal diseases and disorders. However, there is limited evidence to prove this. This article reviews the current applications and evidence regarding submucosal endoscopy while exploring the possible future clinical applications in this field. As our understanding of these procedures improves, the future of submucosal endoscopy could be promising in the fields of diagnostic and therapeutic endoscopy

Transcriptional silencing of Dickkopf gene family by CpG island hypermethylation in human gastrointestinal cancer

AIM: To clarify alterations of Dickkopfs (Dkks) and Kremen2 (Krm2) in gastrointestinal cancer

Spontaneous regression of transverse colon cancer with high-frequency microsatellite instability: a case report and literature review

Abstract Background Spontaneous regression (SR) of colorectal cancer (CRC) is extremely rare, and only few cases have been reported. Although it is not yet clarified, a plausible mechanism for SR of CRC is an immunological event. Case presentation In this report, we present the case of SR of primary CRC in a 78-year-old man. Preoperative colonoscopy was performed, and a type 2 tumor measuring 30 mm in diameter in the transverse colon was detected. The biopsy revealed a poorly differentiated adenocarcinoma. Colectomy was performed 2 months after initial colonoscopy. During the surgery, only a 10-mm ulcer harboring a polypoid lesion measuring 8.5 mm was detected in the resected tissue; no other masses or carcinoma cells were seen on histological examination. Afterwards, the biopsy specimens were reanalyzed, and immunohistological analysis verified this as adenocarcinoma with stroma-infiltrating lymphocytes. Further analysis revealed a loss of two mismatch repair proteins, suggesting sporadic high-frequency microsatellite instability (MSI-H). Conclusion According to previous literature, a common site of SR in CRC is the proximal colon, which is a feature of MSI-H CRC. However, our report showed a rare case of SR of CRC, which was in the transverse colon, with MSI-H present. This report indicates a relationship between immunological features of MSI-H and the occurrence of SR of CRC. A better understanding of this phenomenon and the mechanisms involved will have significant preventive and therapeutic implications for CRC, including anti-PD-1 immune checkpoint inhibitor therapy