Endoscopic ultrasonography for staging of T1a and T1b esophageal squamous cell carcinoma

Abstract

Aim: To investigate the accuracy of Endoscopic ultrasound (EUS) in staging and sub-staging T1a and T1b esophageal squamous cell carcinoma (ESCC).

Methods: A retrospective analysis involving 72 patients with pathologically confirmed T1a or T1b ESCC, was undertaken between January 2005 and December 2011 in Sun Yat-sen University Cancer Center. The accuracy and efficiency of EUS for detecting stages T1a and T1b ESCC were examined.

Results: The overall accuracy of EUS for detecting stage T1a or T1b ESCC was 70.8% (51/72), and the sensitivity was 74.3%. 77.8% (7/9) of lesions originated in the upper thoracic region, 73.1% (38/52) in the mid-thoracic region and 72.7% (8/11) in the lower thoracic region. Multivariate analysis revealed that the diagnostic accuracy of EUS was closely related to lesion length (F = 4.984, P = 0.029).

Conclusion: EUS demonstrated median degree of accuracy for distinguishing between stages T1a and T1b ESCC. Therefore, it is necessary to improve EUS for staging early ESCC.

Keywords: Early cancer; Endoscopic ultrasound; Esophageal cancer; Squamous carcinoma; Stage.

Figure 1

Images of patients with stage T1a or T1b early esophageal squamous carcinoma. A-C: Stage T1a early esophageal squamous carcinoma; A: The lesion visualized by endoscopy and chromoendoscopy with iodine staining; B: The lesion visualized by ultrasonography. The lesion appeared as a hypoechoic line in the first layer, and the outside edge of the second layer was smooth; these two layers represent the mucosa and muscularis mucosa, and thus, the lesion was limited to the mucosa. The third layer (hyperechoic), which represented the submucosa, was intact; C: The post-operative pathology revealed that the tumor had invaded the lamina propria; therefore, this case was confirmed as T1a stage; D-F: Stage T1b early esophageal squamous carcinoma; D: The lesion visualized by endoscopy and chromoendoscopy with iodine staining; E: The lesion visualized by ultrasonography appeared as a hypoechoic line not only in the first and second layers but also in the third layer (hyperechoic), which represents the submucosa; the fourth layer (hypoechoic), which represents the muscularis propria, was intact; F: The postoperative pathology confirmed that the lesion covered the mucosa and had invaded into the submucosa; therefore, the patient was staged as T1b.