Diagnostic value of pink sign of endoscopic iodine staining for early esophageal carcinoma

Abstract

Objective To explore the diagnostic value of pink sign of iodine staining for early esophageal carcinoma. Methods Data of 312 lesions of 306 patients with suspected early esophageal carcinoma who received iodine staining from November 2015 to October 2017 were analyzed retrospectively. Lesions were divided into positive pink sign group and negative pink sign group according to the result of iodine staining. The relationship between pink sign and pathology were analyzed. Lesions recorded onset time of pink sign were divided into 4 groups by the onset time of pink sign, 0-30 s, >30-60 s, >60-90 s and >90-120 s, the diagnostic value of which was assessed with the receiver operating characteristic (ROC) curve. Results Among the 312 lesions, 208 were identified positive pink sign, including 28 of inflammation or low-grade intraepithelial neoplasia (LGIN), 180 of high-grade intraepithelial neoplasia (HGIN) or carcinoma, and 104 lesions were identified negative pink sign, including 69 of inflammation or LGIN, 35 of HGIN or carcinoma. The sensitivity, specificity and accuracy of positive pink sign in the diagnosis of HGIN and early esophageal carcinoma was 83.7%, 71.1% and 79.8%, respectively. Multivariate analysis showed a significant association between the onset time of pink sign and histopathology (P=0.000, OR=0.016, 95%CI=0.042-0.324). The onset time of pink sign was recorded in 89 lesions in the positive group. The area under ROC curve of the onset time of pink sign was 0.899, and the optimal cut-off value was 60 s, which indicated the good validity of the test with the sensitivity, specificity and accuracy of 92.8%, 84.2% and 91.0%, respectively. Conclusion The pink sign of iodine staining for diagnosis of early esophageal carcinoma shows a high consistance rate, especially that appears within 60 s. Key words: Diagnosis; Early esophageal carcinoma; Iodine staining; Pink sign