Differences in Clinicopathology of Early Gastric Carcinoma between Proximal and Distal Location in 438 Chinese Patients

Abstract

Early gastric carcinoma (EGC) in Chinese patients remains poorly understood and endoscopic therapy has not been well established. Here, we compared endoscopic and clinicopathologic features between early proximal gastric carcinoma (PGC, n = 131) and distal gastric carcinoma (DGC, n = 307) in consecutive 438 EGCs diagnosed with the WHO criteria. By endoscopy, PGCs showed protruding and elevated patterns in 61.9%, while depressed and excavated patterns in 33.6%, which were significantly different from those (32.6% and 64.5%) in DGCs. PGCs were significantly smaller (1.9 cm in average, versus 2.2 cm in DGCs), invaded deeper (22.9% into SM2, versus 13% in DGCs), but had fewer (2.9%, versus 16.7% in DGCs) lymph node metastases. Papillary adenocarcinoma was significantly more frequent (32.1%, versus 12.1% in DGCs), as were mucinous and neuroendocrine carcinomas, carcinoma with lymphoid stroma (6.9%, versus 1.6% in DGCs); but poorly cohesive carcinoma was significantly less frequent (5.3%, versus 35.8% in DGCs). The overall 5-year survival rate was 92.9% in EGCs, and PGC patients showed shorter (42.4 months, versus 48.3 in DGCs) survival. Papillary and micropapillary adenocarcinomas and nodal metastasis were independent risk factors for worse survival in EGCs. EGCs in Chinese were heterogeneous with significant differences in endoscopy and clinicopathology between PGC and DGC.

Clinicopathology of Early Gastric Carcinoma: An Update for Pathologists and Gastroenterologists

“…More recently, Lee et al [26] reported a high (18.3%, 9/49) frequency of lymph node metastasis in early papillary adenocarcinoma of Korean patients. The abovementioned results have been confirmed most recently in Chinese patients [14,18]. Compared to early tubular adenocarcinoma, early papillary adenocarcinoma is associated with a significantly worse 5-year survival rate (80.5% compared to 96.8% in early tubular adenocarcinoma, p < 0.05), significantly more submucosal invasion (64.4 vs. 43.6%) ( p < 0.05), and the micropapillary growth pattern (6.8 vs. 0%) ( p < 0.003) [18].…”

“…Compared to distal carcinomas, small proximal gastric carcinomas feature a significantly higher male-to-female ratio (3.1 vs. 1.7, p < 0.05), older mean age (63 years vs. 59, p < 0.05), and the absence of patients younger than 40 years [13]. Similar characteristics have been found in EGCs of the same patient population [14]. The results provide the pathologic evidence on possible Lgr5 + stem cell-driven tumorigenesis mechanism in those 2 areas.…”

“…A most recent systematic review of the world literature in 42 qualified studies shows low, but substantial, nodal metastasis rates of 6% for intramucosal carcinoma, 9% for EGC without lymphovascular invasion, 13% for the intestinal-type EGC, 13% for EGC with an elevated growth pattern, and 8% for EGC in the size smaller than 2 cm [47]. In Korea[,] Kang et al [52] reported an overall 12.6% nodal metastasis rate in 478 EGC radical resection cases, and no relationship was found between clinicopathologic features and nodal metastasis in 270 pT1a tumors (Table 2), parallel to the findings in Chinese patients [14,18]. Importantly, the current criteria for extended indications for ESD were found to be problematic for prediction of risk of nodal metastasis in intramucosal signet ring cell carcinoma (Tables 1, 2).…”

“…In reality, invasion in the gastric lamina propria is difficult to detect on routine histology sections, and there is no reliable/established pathologic diagnostic criterion for lamina propria invasion. Nevertheless, intramucosal tubular adenocarcinoma has been confirmed to have a low risk of lymph node metastasis [14,18,19] and, therefore, can be safely removed endoscopically. In histopathology, most early tubular adenocarcinomas originate in the isthmus/neck of a gastric unit along the lesser curvature in the distal stomach [13,20].…”

“…Compared to early tubular adenocarcinoma, early papillary adenocarcinoma is associated with a significantly worse 5-year survival rate (80.5% compared to 96.8% in early tubular adenocarcinoma, p < 0.05), significantly more submucosal invasion (64.4 vs. 43.6%) ( p < 0.05), and the micropapillary growth pattern (6.8 vs. 0%) ( p < 0.003) [18]. The cases with a micropapillary growth pattern were all associated with early papillary adenocarcinoma and had a high (50%, 2/4) nodal metastasis rate, though in a small sample [14,18]. Thus, a growing body of the evidence suggests a dismal prognosis in early papillary adenocarcinoma, primarily due to deeper invasion, higher association with the micropapillary growth pattern, more frequent lymphovascular invasion and nodal metastasis.…”