Endoscopic submucosal dissection for undifferentiated early gastric cancer as the expanded indication lesion

Endoscopic submucosal dissection (ESD) has become the standard endoscopic treatment for early gastric cancer without lymph node metastasis. At present, undifferentiated type intramucosal cancers without ulcer findings <20 mm in size are often chosen as endoscopic treatment lesions for expanded indication. The purpose of this study was to examine the outcome of ESD treatment in undifferentiated carcinomas.

Forty-six patients who had undergone ESD from July 2002 until July 2010, where the final pathological diagnosis was undifferentiated carcinoma, were assessed for the en-bloc resection ratio, the accuracy rate of depth or extent of diagnosis and survival.

In endoscopic ultrasonography studies, the accuracy rate of mucosal lesions was 86%. The rate of en-bloc resection was 91% (42/46) and 5 cases had a positive margin. Four cases had a positive margin in cases of piecemeal resection. Five cases underwent additional surgery, and residual cancer was found in 1 case. There were 2 cases of perforation, 2 of delayed hemorrhage, and no cases of delayed perforation. One case died of multiple liver metastases and 1 died of hepatocellular carcinoma. After a maximum of 8 years, an average of 3.8 years of observation, including 7 cases who had undergone additional surgery, recurrence occurred in only 1 case of liver metastasis.

In this study the lesions of undifferentiated adenocarcinoma, which were limited to the mucosa, <20 mm in diameter and had been completely resected, showed no recurrence and were indicated for endoscopic treatment.