Hemoglobin content in intramucosal gastric carcinoma as a marker of histologic differentiation: a clinical application of quantitative electronic endoscopy

Background: It has been suggested that the endoscopic color of intramucosal gastric carcinoma is correlated with mucosal vascularity within the carcinomatous tissue. The development of electronic endoscopy has made it possible to quantitatively measure the mucosal hemoglobin volume, using a hemoglobin index. The aims of the present study were to investigate whether this hemoglobin index is useful for evaluating the change in color of early gastric carcinoma and to verify the diagnostic value of this index for distinguishing between histologic degrees of differentiation. Methods: The ratios of the hemoglobin index of cancerous and non-cancerous mucosa for 26 differentiated and 18 undifferentiated intramucosal gastric carcinomas were determined from electronic endoscopic imaging data. Results: The mean ratio of the hemoglobin index of cancerous and non-cancerous mucosa in the differentiated gastric carcinomas was higher than it was in the undifferentiated carcinomas (1.23: 95% CI [1.15, 1.31] versus 0.84: 95% CI [0.81, 0.88]). The sensitivity and specificity for discriminating undifferentiated from differentiated carcinoma were 100% and 85%, respectively. Conclusion: Measurement of mucosal hemoglobin volume (hemoglobin index) is useful for evaluating the endoscopic color of early gastric carcinoma quantitatively and may be helpful in distinguishing differentiated from undifferentiated carcinoma.