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

BACKGROUND: 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.

METHOD: 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.

RESULTS: 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.

CONCLUSION: 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.