Abstract
BACKGROUND: Performing additional surgery after noncurative endoscopic submucosal dissection (ESD) for early gastric cancer is controversial. Our aims are to clarify the risk factors for lymph node metastasis (LNM) and local residual cancer (RC) after noncurative ESD and to determine recommendations for additional treatment. METHODS: Of the 1483 patients who underwent ESD for early gastric cancer between January 2012 and April 2020, we retrospectively analyzed 151 patients diagnosed as having a lesion not meeting the curative criteria after ESD. Of these patients, 100 underwent additional gastrectomy, and 51 were observed without surgery. RESULTS: Surgical specimens showed LNM in 14 patients (14.0%) and local RC in 7 (7.0%). However, 81 patients (81.0%) had neither of these malignancies. Multivariate analysis revealed that a positive lymphatic invasion (P = 0.035) and an undifferentiated type (P = 0.047) were independent risk factors for LNM, whereas a positive horizontal margin (P = 0.010) was an independent risk factor for local RC. Furthermore, the prevalence of LNM was significantly higher in patients with both positive lymphatic and vascular invasions. In the additional gastrectomy group, 3 patients (3.0%) had recurrences, and 2 patients (2.0%) who had distant recurrences died of gastric cancer. In the observation group, recurrence was observed in 3 patients (5.9%). One patient (2.0%) who had liver metastasis died of gastric cancer. Of the 2 patients (3.9%) who had local recurrences, one underwent additional ESD, and the other without additional ESD died of other disease. The 5-year overall survival rates in the additional gastrectomy and observation groups were 87.4% and 73.8%, respectively (log-rank test, P = 0.008). CONCLUSION: Following noncurative ESD for early gastric cancer, we recommend an additional gastrectomy with lymph node dissection for patients with lymphovascular invasion and/or undifferentiated type. Careful follow-ups without additional surgery may be acceptable for patients with advanced age, severe comorbidity, or no lymphovascular invasion.