Additive Effects of Evaluating Micro-Surface and Microvascular Patterns Using Magnifying Endoscopy with Narrow-Band Imaging for Gastric Cancer

Abstract No studies have compared the performance of microvascular and micro-surface patterns alone with their combination in magnifying endoscopy with narrow-band imaging for diagnosing gastric cancer. This study aimed to clarify the difference in diagnostic performance between these methods. Thirty-three participating endoscopists underwent specialized training in magnifying endoscopy evaluated microvascular and micro-surface patterns for images of 106 cancerous and 106 non-cancerous cases. If classified as “irregular”, the lesion was diagnosed as cancerous. To evaluate diagnostic performance, we compared the diagnostic accuracy, sensitivity, and specificity among the methods. Performance-related items did not significantly differ between the microvascular and micro-surface patterns. However, the diagnostic accuracy and sensitivity were significantly higher when using the combination of these methods than when using the microvascular pattern alone (percentage [95% confidence interval]: 82.1% [76.4–86.7] vs. 76.4% [70.3–81.6], P = 0.0005; and 69.8% [60.5–77.8] vs. 63.2% [53.7–71.8], P = 0.0082, respectively). The additive effects on diagnostic accuracy and sensitivity were 5.7% and 6.6%, respectively. The combination of micro-surface and microvascular patterns has superior diagnostic accuracy and sensitivity for diagnosing gastric cancer than the evaluation method using microvascular pattern alone. Our results may contribute to improving the diagnosis of gastric cancers.