Long-Term Outcomes of Endoscopic Submucosal Dissection of Undifferentiated-Type Early Gastric Cancer

Early Detection of Malignant Cells in Gastric Lavage via Hexokinase 2 and Single-Cell Sequencing for Gastric Cancer Diagnosis

Objective

Gastric cancer represents a significant global health challenge due to its high prevalence and mortality rates, largely attributed to the limitations of current screening methods, such as endoscopy, which impede early diagnosis. This study presents an innovative method for early detection by identifying exfoliated tumor cells in gastric lavage, aiming to overcome challenges related to patient compliance and the variability in endoscopist expertise.

Methods

Hexokinase 2 (HK2), a metabolic marker, was utilized to identify exfoliated tumor cells with heightened glycolytic activity in gastric lavage fluid. The malignancy of these HK2-positive, high-glycolytic tumor cells was further validated using single-cell sequencing (SCS), specifically through genome-wide copy number variation analysis.

Results

A total of 60 individuals were assessed, including 10 patients with gastric cancer (9 at stage IA and 1 at stage IIA), 26 patients with precancerous lesions, 15 patients with benign gastric conditions, and 9 healthy controls. The HK2 assay demonstrated an 80% diagnostic sensitivity for stages IA and IIA of gastric cancer and a 96% diagnostic specificity in distinguishing benign conditions from healthy controls. Importantly, the assay exhibited 57% sensitivity for cases of severe dysplasia, underscoring its potential for early gastric cancer detection and preventive diagnostics.

Conclusion

The study highlights the feasibility of a novel gastric lavage-based HK2 assay, complemented by SCS for malignancy confirmation, as a highly accurate method for the early detection of gastric cancer. This approach offers a promising alternative to traditional gastroscopy, particularly for early-stage disease, potentially enhancing detection rates and improving patient outcomes.

Therapeutic approach to non-curative resection after endoscopic treatment in early gastric cancer

Background: Endoscopic resection is indicated for early or superficial gastrointestinal neoplasms with a negligible risk of lymph node metastasis. This procedure could preserve the organ while allowing en bloc resection of tumors, irrespective of the size and location of the lesion. Histological evaluation of the resected specimen determines whether curative resection, which implies a favorable long-term outcome, was achieved. If the resected specimen reveals non-curative, additional treatment is necessary as it is strongly associated with recurrence.Current Concepts: Surgical resection is recommended after non-curative resection of gastrointestinal neoplasms. However, rather than surgical resection, additional endoscopic treatment can be recommended if non-curative resection is solely because of the positive involvement at the horizontal resection margin without any other findings compatible with the non-curative resection criteria.Discussion and Conclusion: Adopting precise indications of endoscopic resection is important to reduce the risk of non-curative resection. If curative resection is not achieved after endoscopic resection, additional treatment should be considered to prevent local recurrence as well as lymph node metastasis.

Endoscopic treatment for early gastric cancer

Background: In Korea, the number of screening endoscopies to detect early stage gastric neoplasms has increased exponentially following the active implementation of the National Cancer Screening Program.Current Concepts: Endoscopic treatment, including endoscopic mucosal resection and endoscopic submucosal dissection, is recognized as a minimally invasive treatment method with low morbidity and mortality for gastric dysplasia or early gastric cancer. Owing to improvement in the detection of early gastric cancer and advances in techniques, cases of endoscopic resection have increased and indications have been expanded. Endoscopic resection can preserve gastric function with excellent maintenance of the patient’s quality of life, and previous studies have shown better long-term follow-up outcomes compared to those with surgery. However, the fundamental limitation of endoscopic procedures is that gastric lymph-node dissection is not possible using endoscopic resection.Discussion and Conclusion: Although the usefulness of endoscopic resection is proven for tumors with a very low risk of lymph-node metastasis, follow-up examination using endoscopy and computed tomography should be performed for at least 5 years after curative resection of early gastric cancer.