Factors Associated with Local Recurrence and Incomplete Resection in Endoscopic Submucosal Dissection for the Treatment of Early Gastric Cancers

Abstract

Backgrounds: Endoscopic mucosal resection (EMR) for early gastric cancers spread widely because it was minimally invasive procedure compared with surgical resection, but local recurrence after EMR was occasionally confirmed. Endoscopic submucosal dissection (ESD) which was developed to allow safe resection for a larger lesion in a single piece contributed to lower rate of local recurrence. However, we still experience recurrence cases after ESD. In this study, we analyzed the cases that developed local recurrence after ESD, and clarified the factors associated with local recurrence and incomplete resection. Patients and Methods: ESD was performed using insulated-tipped knife, flex knife and mucosectome. A total of 269 consecutive patients with intestinal-type early gastric cancer were removed by ESD at Okayama University Hospital and Tsuyama Central Hospital from Mach 2001 to September 2005. The resectability of ESD specimens was carefully evaluated endoscopically and pathologically. When the tumor invaded to the lateral margin, it was classified as incomplete resection. Results: Complete en-bloc resection rate, which was evaluated pathologically, was 80.7%. Local recurrence was found in 4 cases (1.5% of all cases) with a mean follow up periods of 10 months (2 - 45 months). One patient underwent additional ESD and the rest had surgical resection. Removed specimens revealed that all recurrence lesions arising after ESD were mucosal cancers, and no lymphnode metastasis was seen in surgical resected patients. We analyzed factors associated with local recurrence by Mann-Whitney analysis for continuous variable and chi-square analysis for discontinuous variables. The following variables were selected: size (mm), appearance (flat, depressed vs. protruded), location in the stomach (upper vs. middle vs. lower), ulcer findings (presence vs. absence), and invasion to the lateral margin of the reseted specimen (presence vs. absence). Only the presence of tumor invasion to the lateral margin (i.e. incomplete resection) was significantly related to local recurrence (p = 0.0010). Then, we analyzed factors associated with incomplete resection by logistic regression analysis. Tumor size (odds ratio (OR) = 1.032, 95% confidence interval (CI) = 1.003 - 1.062), tumor location (upper vs. lower; OR = 3.2, 95% CI = 1.3 - 7.6), and presence of ulcer findings (OR = 2.6, 95% CI = 1.0 - 6.7) were identified as significantly associated factors with incomplete resection. Conclusions: To avoid local recurrence after ESD, it is important to remove early gastric cancer under the tumor-free condition at the lateral margin of the resected specimens.