Clinical Characteristics of Intramucosal Gastric Cancers with Lymphovascular Invasion Resected by Endoscopic Submucosal Dissection.

Introduction: In patients with intramucosal gastric cancer (MGC) who have undergone endoscopic submucosal dissection (ESD), lymphovascular invasions (LVIs) such as lymphatic invasion or venous invasion are considered risk factors of lymph node metastasis (LNM). However, the rate of LNM in MGCs with LVI and their clinicopathological features are unclear.

Objective: This study aimed to examine the rate of LNM and clinical characteristics of MGCs with LVI as compared to MGCs without LVI and minimally invasive submucosal gastric cancers (mSMGCs) with LVI.

Methods: Among the early gastric cancers excluding the remnant stomach who underwent ESD at our hospital from July 2003 to September 2018, the MGCs with LVI were included as the target in this study. MGCs without LVI and mSMGCs with LVI were also included as control.

Results: Seventeen lesions in 17 patients with MGCs with LVI, 1,149 lesions in 865 patients with MGCs without LVI, and 29 lesions in 29 patients with mSMGCs with LVI were analyzed. LVI was noted in 1.5% (17/1,166) of MGC cases. During follow-up of the MGC cases with LVI, there were no LNM or recurrences reported, and 14 patients survived and 3 died of other diseases. However, LNM occurred in 2 cases of mSMGC. Among the MGC cases, univariate analysis showed that the pap component, elevated type, and tumor diameters of 20 mm or more were statistically significant factors with respect to LVI, while multivariate analysis showed that the pap component was the only significant factor.

Conclusion: Careful follow-up may be appropriate for MGCs with LVI due to the low risk of LNM. Additionally, the pap component is a significant factor in MGCs with LVI.