Histopathological validation of magnifying endoscopy for diagnosis of mixed-histological-type early gastric cancer

Abstract

BACKGROUND The undifferentiated-type (UDT) component profoundly affects the clinical course of early gastric cancers (EGCs). However, an accurate preoperative diagnosis of the histological types is unsatisfactory. To date, few studies have investigated whether the UDT component within mixed-histological-type (MT) EGCs can be recognized preoperatively. AIM To clarify the histopathological characteristics of the endoscopically-resected MT EGCs for investigating whether the UDT component could be recognized preoperatively. METHODS This was a single-center retrospective study. First, we attempted to clarify the histopathological characteristics of the endoscopically-resected MT EGCs with emphasis on the UDT component. Histopathological examination investigated each lesion’s UDT component: (1) Whole mucosal layer occupation of the UDT component; (2) UDT component exposure to the surface of the mucosa; and (3) existence of a clear border between the differentiated-type and UDT components. Then, preoperative endoscopic images with magnifying endoscopy with narrow-band imaging (ME-NBI) were examined to identify whether the endoscopic UDT component finding was recognizable within the area where it was present in the histopathological examination. The preoperative biopsy results and comparative relationships between endoscopic and histopathological findings were also examined. RESULTS In the histopathological examination, the whole mucosal layer occupation of the UDT component and exposure of the UDT component to the mucosal surface were observed in 67.3% (33/49) and 79.6% (39/49) of samples, respectively. A clear distinction of the border between the differentiated-type and UDT components could not be drawn in 65.3% (32/49) of MT lesions. In the endoscopic examination, the preoperative endoscopic images showed that only 24.5% (12/49) of MT EGCs revealed the UDT component within the area where it was present histopathologically. Histopathological UDT predominance was the single significant factor associated with the presence of the endoscopic UDT component finding (61.5% vs 11.1%, P = 0.0009). Only 26.5% (13/49) of the lesions were diagnosed from the pretreatment biopsy as having a UDT component. Combined results of the pretreatment biopsy and ME-NBI showed the preoperative presence of the UDT component in 40.8% (20/49) of MT EGCs. CONCLUSION Recognition of a UDT component within MT EGCs is difficult even when pretreatment biopsy and ME-NBI are combined. Endoscopic resection plays a significant role in both treatment and diagnosis.

Risk factors of additional surgery after non-curative endoscopic submucosal dissection for early gastric cancer

“…Thus, it is meaningful to diagnose mixed type early gastric cancer before ESD procedures, which might reduce the incidence rates of additional surgery after ESD caused by incorrect pretreatment diagnosis of histological type. Magnifying endoscopy combined with narrow-band imaging and biopsy was a promising measure for diagnosing mixed histologic type EGC [28,29].…”

Relationship between histological mixed-type early gastric cancer and lymph node metastasis: A systematic review and meta-analysis

“…After scanning titles and abstracts, 47 citations remained for full-text assessment. The search results and selection process are summarized in Fig 1 . Twenty-three studies were excluded for the following reasons: 9 studies did not include histological mixed-type classification [16,[26][27][28][29][30][31][32][33]; 6 did not directly mention the number of LNM cases [34][35][36][37][38][39]; 3 were considered to have unreliable data [40][41][42]; 2 were not confined to EGC [12,43]; and 3 were not accessible online. Finally, 24 studies were deemed eligible for the meta-analysis.…”