Published online Sep 28, 2016. doi: 10.3748/wjg.v22.i36.8203
Peer-review started: March 18, 2016
First decision: July 12, 2016
Revised: July 25, 2016
Accepted: August 8, 2016
Article in press: August 8, 2016
Published online: September 28, 2016
Processing time: 194 Days and 15.4 Hours
To investigate clinicopathological features of early stage gastric cancer with enteroblastic differentiation (GCED).
We retrospectively investigated data on 6 cases of early stage GCED and 186 cases of early stage conventional gastric cancer (CGC: well or moderately differentiated adenocarcinoma) who underwent endoscopic submucosal dissection or endoscopic mucosal resection from September 2011 to February 2015 in our hospital. GCED was defined as a tumor having a primitive intestine-like structure composed of cuboidal or columnar cells with clear cytoplasm and immunohistochemical positivity for either alpha-fetoprotein, Glypican 3 or SALL4. The following were compared between GCED and CGC: age, gender, location and size of tumor, macroscopic type, ulceration, depth of invasion, lymphatic and venous invasion, positive horizontal and vertical margin, curative resection rate.
Six cases (5 males, 1 female; mean age 75.7 years; 6 lesions) of early gastric cancer with a GCED component and 186 cases (139 males, 47 females; mean age 72.7 years; 209 lesions) of early stage CGC were investigated. Mean tumor diameters were similar but rates of submucosal invasion, lymphatic invasion, venous invasion, and non-curative resection were higher in GCED than CGC (66.6% vs 11.4%, 33.3% vs 2.3%, 66.6% vs 0.4%, 83.3% vs 11% respectively, P < 0.01). Deep submucosal invasion was not revealed endoscopically or by preoperative biopsy. Histologically, in GCED the superficial mucosal layer was covered with a CGC component. The GCED component tended to exist in the deeper part of the mucosa to the submucosa by lymphatic and/or venous invasion, without severe stromal reaction. In addition, Glypican 3 was the most sensitive marker for GCED (positivity, 83.3%), immunohistochemically.
Even in the early stage GCED has high malignant potential, and preoperative diagnosis is considered difficult. Endoscopists and pathologists should know the clinicopathological features of this highly malignant type of cancer.
Core tip: We evaluated the comparison of clinicopathological features between 6 cases of early stage gastric cancer with enteroblastic differentiation (GCED) and 186 cases of early stage conventional gastric cancer (CGC: well/ moderately differentiated adenocarcinoma). Lymphatic, venous, and submucosal invasion rates were higher in GCED than CGC (33.3% vs 2.3%, 66.6% vs 0.4%, 66.6% vs 11.4% respectively, P < 0.01). In addition, Glypican 3 was the most sensitive marker for GCED (positivity, 83.3%), immunohistochemically. GCED has high malignant potential even at an early stage, and preoperative diagnosis is considered difficult. Further investigations are needed to establish optimal treatment approaches for GCED.