Invasive features of superficial oesophageal squamous cell carcinoma—analysis of risk factors for lymph node metastasis

There are currently no studies that have examined the clinicopathological factors in detail, including the histological images of the invasive front, and the risk of lymph node metastasis (LNM) in superficial oesophageal squamous cell carcinoma (SESCC). This study aimed to develop an algorithm that contributes to a better assessment of the risk of LNM and recurrence in SESCC. Clinicopathological factors, such as submucosal (SM) invasion distance, were examined in 88 surgically resected cases of SESCC. An SM invasion distance of 600 μm was the statistically best customer value for LNM (p = 0.0043). To obtain a histological image of the invasive front, we evaluated modified tumour budding (MBD) by modifying the number of tumour foci constituent cells and foci in tumour budding. We also evaluated the smallest number of tumour foci. Using these factors, we developed an algorithm to predict the risk of LNM. The best algorithm was created using an SM invasion distance of 600 μm and an index of 5 or more foci consisting of five or fewer tumour cells in the MBD (MBD5 high-grade ≥ 5), which was also significantly associated with recurrence-free survival (p = 0.0305). Further study of the algorithm presented in this study is expected to improve the quality of life of patients by selecting appropriate additional treatments after endoscopic resection and appropriate initial treatment for SESCC.