Background: In the treatment of early gastric cancer, patients suitable for endoscopic submucosal dissection (ESD) are selected on the basis of endoscopic findings and biopsy results, while the final diagnosis is confirmed by examination of the resected specimen. Aim: To examine the discrepancies between clinical and pathological findings before and after ESD. Materials and Methods: We retrospectively identified 335 lesions treated by ESD for early gastric cancer at the National Cancer Center between 2020 and 2025, compared the endoscopic, biopsy and pathological findings, and identified the factors associated with discrepancy. Result: At least one of the three pre-treatment parameters was discordant in 175 lesions (52.2%). Of the 249 lesions judged to be ulcer-free on endoscopy, 51 (20.5%) were ulcerated histologically, while 28 lesions were overestimated (P<0.05). Underestimation of ulceration was more likely in lesions located in the upper or middle third of the stomach (OR 2.17, 95% CI 1.22–3.99) and in lesions measuring ≥20 mm (OR 1.68, 95% CI 1.00–2.84). Of the 110 lesions diagnosed as high-grade dysplasia on biopsy, 36 (32.7%) contained adenocarcinoma in the resected specimen, one of which was of undifferentiated type. Of the remaining 18 undifferentiated lesions, 6 (33.3%) had been diagnosed as differentiated type before treatment. Submucosal and lymphovascular invasion were associated with a tumor size of ≥20 mm (OR 3.58 and 3.15) and undifferentiated histology (OR 4.47 and 7.56); all P<0.01. Conclusion A significant discrepancy was observed between the pre- and post-ESD clinicopathological findings.

Introduction: In 2018, the overall colorectal cancer (CRC) incidence rate was 3.6%, according to the National Cancer Center of Mongolia (NCCM), and the incidence of colorectal cancer has increased slightly in recent years. According to cancer stages, late stage cancer has a 5-year survival rate of 51%, while early stage cancer has a 5-year survival rate of 79%. The overall survival rate of colorectal cancer in Mongolia has not been studied in precisely. In Asia, the 5-year survival rate for colorectal cancer was 60%. Therefore, this study investigated the colorectal cancer survival rate and prognostic factors at NCCM. Methods: A total of 108 patients diagnosed with CRC at NCCM’s General Surgery Department from 2013 to 2015 were used in this retrospective cohort study. The Kaplan-Meier method was used to develop the survival graphs, which were then compared using the Log-rank test. Results: The median survival time was 42 months, with a 95% CI (38.55-45.66). A 5-year period, the overall survival rate for CRC was 61.2%. Survival rates at the I, II, III, and IV stages were 100%, 75%, 65.4%, and 13.5%, respectively. There was a significant difference in CRC survival rates across all stages (p=0.0001). There was a statistically significant difference in determining the relationship between adjuvant chemotherapy and survival rate (p=0.0003). Conclusion The outcome of the surgery is determined by the CRC stage. The postoperative survival rate (61.2%) is directly related to tumor stage, peripheral glandular metastasis, distant metastasis, and chemotherapy effects.