Outcomes and precautions of endoscopic submucosal dissection for undifferentiated-type early gastric cancer

Abstract

Objectives: Since the development of techniques for endoscopic submucosal dissection (ESD), the indication range of endoscopic resection (ER) has been extended in early gastric cancer (EGC) treatment. For undifferentiated-type EGC, tumors with an intramucosal depth of invasion, no ulceration and a diameter of 20 mm or less were included in the expanded indications for ER in the Japanese Gastric Cancer Treatment Guidelines 2010. Nonetheless, because of difficulty in detecting lesions that meet the criteria for ER, the number of endoscopically resected cases of undifferentiated-type EGC is less than that of differentiated-type EGC. Methods: We retrospectively investigated the outcomes of ESD in 38 patients with 40 lesions of EGC in which the dominant pathological type was confirmed to be undifferentiated (signet ring cell carcinoma, poorly differentiated adenocarcinoma, mucinous adenocarcinoma) on histological examination of resected specimens. Results: Margin involvement and submucosal infiltration were common noncurative factors. Precise evaluation of the area and depth of lesions is a problem to be solved. Among a total of five patients with involved or uncertain horizontal margins, one of two patients who underwent additional surgery had residual cancer, and one of three patients who were observed had recurrence. Conclusions: Undifferentiated-type EGC with a positive horizontal margin may relapse after ESD. It is therefore essential to precisely evaluate the area of the lesion and to perform resection with an adequate safety margin to decrease the risk of recurrence.

Endoscopic Submucosal Dissection versus Surgery for Undifferentiated-Type Early Gastric Cancer: A Systematic Review and Meta-Analysis

“…However, the recurrence rate was much higher in the ESD group. Most previous studies reported that the overall survival rate of patients with UD-EGC treated with ESD was approximately 90% until the end of follow-up [ 14 , 32 - 34 ]. The interval of surveillance with esophagogastroduodenoscopy after ESD and after surgery was not identical in most studies.…”

Mixed poorly differentiated adenocarcinoma in undifferentiated-type early gastric cancer predicts endoscopic noncurative resection

“…For instance, comparisons between surgical specimens of mixed PDA and pure SRC have revealed higher frequencies of lymph node metastasis and submucosal invasion in the former [4][5][6]. Treatment outcomes and prognoses of UD-type EGCs after endoscopic treatment have also been studied, and the suitability of endoscopic treatment in these cases has been discussed [7][8][9]. However, mixed PDA and pure SRC have not been studied separately.…”

Endoscopic Resection of Undifferentiated-type Early Gastric Cancer

“…Short-term outcomes, including en bloc resection, complete resection, curative resection, and complication rates of ER for UD-EGC, were reviewed (Table 2) [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. En bloc resection was homogenously defined in the studies as the resection of the tumor in one piece with no endoscopically residual tumor, i.e., tumor resected in one piece without fragmentation.…”

“…Kang et al [22] who recorded a 0% local recurrence, reported that incomplete resection occurred when the tumor was resected in multiple fragments, with resected margins positive for cancer invasion or lymphovascular infiltration. The 5-year overall survival (5YOS) was reported to range from 93.0% to 98.6% in curative resection with the expanded criteria [17,19,26,28,29,31]. Inokuchi et al [28] reported a 5YOS of 93.3% after curative resection, with one patient mortality due to another disease at 49.3 months after ESD (data without cause of death).…”

“…These rates were relatively high in the 2 studies that included patients who refused surgery and those who had endoscopic ulceration. Three studies, especially those that included MAC, showed relatively high submucosal invasion rates [25,28,31]. Although ESD was performed based on the expanded criteria, the proportion of lesions exceeding 2 cm in ESD specimens was reported to be up to 53.2% [31], which represented the inaccuracy and difficulty in estimating the lesion endoscopically in UD-EGC.…”