Can further gastrectomy be avoided in patients with incomplete endoscopic resection?

Endoscopic resection (ER) is a widely accepted treatment for patients with early gastric cancer (EGC) with no lymph node metastasis. Occasionally, however, additional surgery is needed due to an incomplete resection. The purpose of this study was to detect clinical factors which might identify patients at greater risk of additional surgery after ER and to suggest an alternative treatment strategy for these patients.

This study retrospectively analyzed 350 patients with gastric cancer who underwent radical gastrectomy and lymphadenectomy after ER in a single institution between July 2004 and July 2014. Risk factors for incomplete resection were identified using binary logistic multiple regression tests and a classification and regression tree analysis.

Residual cancer cells were found in the remnant stomach or lymph node in 96 patients (27.4%). In multivariate analysis, lymphovascular invasion (p < 0.001, odds ratio [OR] 5.619) and depth of invasion greater than the second submucosal layer (SM2) (p < 0.01, OR 3.224) were independent risk factors for lymph node metastasis. Positive resection margin (p < 0.001, OR 7.565), depth of invasion to mucosa (M) and the first submucosal layer (SM1) (p < 0.001, OR 4.219), and size over 3 cm (p < 0.029, OR 2.306) were significant risk factors for residual tumor in the remnant stomach. Of 106 patients who had invasion of the M or SM1 without lymphatic invasion at the time of ER, residual cancer was found in 53 patients. Of these 53 patients, 50 (94.3%) had residual cancer in the mucosal layer and only one had lymph node metastasis.

In patients with EGC with M or SM1 invasion without lymphovascular invasion at the time of ER, who had an incomplete resection, additional endoscopic treatment or close monitoring can be performed instead of additional surgery, especially in patients who are unable to tolerate gastrectomy, for example elderly patients or those with comorbidities.