Background: Accurate tumor size measurement is critical for selecting proper candidates for endoscopic resection (ER) of early gastric cancer (EGC). However, size discrepancy between endoscopic size and pathologic size often occurs during ER for EGC.
Objective: The purposes of this study were to investigate the clinicopathological characteristics related to size discrepancy and the clinical implications of size discrepancies in terms of therapeutic outcomes.
Methods: Between April 2006 and June 2013, a total of 820 patients with 826 EGCs underwent ER. Enrolled lesions were categorized into the following three groups based on size discrepancy between endoscopic size and pathologic size: well-estimated (N = 308), underestimated (N = 215), or overestimated (N = 303) lesions. The well-estimated group was defined as lesions with a ratio of endoscopic size to pathologic size from 0.7 to 1.3.
Results: The overall median size discrepancy was 5.0 mm (interquartile range 2.0-9.0). Size, location, macroscopic type, primary tumor stage, and histology differed significantly between the three groups. Larger size [odds ratio (OR) 5.07, 95 % confidence interval (CI) 3.38-7.59, p < 0.001], flat/depressed type (OR 1.71, 95% CI 1.15-2.55, p = 0.008), and undifferentiated histology (OR 2.24, 95% CI 1.31-3.83, p = 0.003) were independent risk factors for endoscopic size underestimation in multivariate analysis. Smaller size (OR 10.95, 95% CI 4.64-25.87, p < 0.001) was the only independent predictor for endoscopic overestimation of size. Significantly lower complete resection and curative resection rates were detected in the underestimated group compared with the well-estimated group, while the complete resection rate in the overestimated group tended to be higher than in the well-estimated group. There was no significant difference of curative resection rate between the overestimated and the well-estimated groups.
Conclusions: Larger size, flat/depressed type, and undifferentiated histology of EGC carry a significant risk for endoscopic underestimation of lesion size, which results in the lower rates of complete and curative resections for EGC. Further studies to reduce size discrepancy are warranted.