Validity of additional surgical resection by comparing the operative risk with the stratified lymph node metastatic risk in patients with early gastric cancer after endoscopic submucosal dissection

BACKGROUND: Treatment guidelines for early gastric cancer (EGC) recommend additional gastrectomy for lesions which do not achieve curative resection after ESD, due to the potential risk of lymph node metastasis (LNM). However, many cases are found to have no LNMs, and additional gastrectomy itself can be a considerable risk especially in elderly patients. METHODS: We retrospectively stratified the risk of LNM according to the total number of four LNM risk factors (RFs) that resulted in non-curative resection for ESD in 861 EGC patients who underwent gastrectomy. Next, we compared this stratification risk to the surgical risk based on the National Clinical Database (NCD) risk calculator in 58 patients who underwent additional gastrectomy. RESULTS: As the total number of LNM RFs increased, the frequency of LNM also increased significantly (0/1RF 0.76%, 2RFs 15.08%, 3RFs 33.87%, 4RFs 50.00%; p < 0.01). The estimated frequency of LNM was found to be lower than the predicted value of in-hospital mortality rate based on the NCD risk calculator in 25.0% of 0/1RF patients. CONCLUSION: These findings indicate, at least, that we should discuss the indication of additional gastrectomy individually for each patient from both perspectives of LNM and surgical risks.