Diagnostic yield of conventional endoscopy with endoscopic ultrasonography for submucosal invasion of superficial esophageal squamous cell carcinoma: a post hoc analysis of multicenter prospective confirmatory study (JCOG0508).

While the accurate depth diagnosis in cSM ESCC was difficult to make, the clinical diagnosis of SM2 with both conventional endoscopy and EUS was significantly associated with pSM. Furthermore, diagnostic ER could be recommended to confirm the pathological diagnosis especially in cSM1 lesions with both conventional endoscopy and EUS.