Clinicopathological features and outcomes of esophageal lesions containing a basal layer type squamous cell carcinoma component

Purpose: Basal layer type squamous cell carcinoma (BLSCC) is a unique type of squamous cell carcinoma (SCC), characterized by high-grade dysplastic cells occupying the lower half of the epithelium. So far, such special lesions do not seem to attract much attention. The aim of this study was to investigate the clinicopathological features and prognosis of esophageal squamous carcinoma lesions with a BLSCC component.

Materials and methods: Between January 2011 and January 2018, 96 patients with esophageal squamous cell carcinoma underwent endoscopic submucosal resection in our hospital were retrospectively analyzed. Patients were divided into BLSCC or typical SCC groups according to the presence or absence of a BLSCC component. The endoscopic findings were compared between the two groups. Furthermore, patients were followed up until October 2018 to compare recurrence rates.

Results: BLSCC components were detected in 32 (33.3%, 32/96) lesions. Among them, 13 (40.62%, 13/32) were BLSCC predominant. The intraepithelial papillary capillary loops of 7 pure BLSCC showed type B1 under narrow-band imaging. Single-factor and multivariate analyses indicated that five or more independently scattered, deep-stained spots in iodine-unstained areas were significantly predictive of the presence of BLSCC components (OR=4.837, P=0.015). All patients of typical SCC group survived, but one of BLSCC group died for distant metastases during the follow-up period. The 1-year cumulative recurrence rate (CRR) of BLSCC group were 3.4%, lower than that of typical SCC group (7.1%). Although no significant difference of CRR was seen between the two groups (P>0.05), the 2-year CRR of BLSCC group increased to 11.9%, being higher than that of typical SCC group (7.1%).

Conclusion: The presence of multiple, scattered stained spots in iodine-unstained areas was predictive of BLSCC components. Such lesion should be treated actively and subject to a more rigorous follow-up protocol due to a higher likelihood of late recurrence.