The risk factors for lymph node metastasis in early gastric cancer patients who underwent endoscopic resection: is the minimal lymph node dissection applicable? A retrospective study.

PURPOSE: The purpose of this study was to identify risk factors associated with lymph node (LN) metastasis in early gastric cancer patients who underwent endoscopic resection (ER) and to evaluate the feasibility of minimal LN dissection in these patients.
METHODS: From January 2001 to March 2011, patients who underwent gastrectomy with lymphadenectomy due to the potential risk of LN metastasis after ER were enrolled at National Cancer Center, Korea. The incidence, risk factors, and distribution of LN metastasis were evaluated.
RESULTS: Of the 147 enrolled patients, the LN metastasis was identified in 12 patients (8.2%). The incidence of LN metastasis was not significantly increased in patients with submucosal invasion, lymphovascular invasion, and mixed undifferentiated histology [odds ratio (OR), 5.55, 1.349, and 0.387; 95% confidence interval (CI), 0.688-43.943, 0.405-4.494, and 0.081-1.84, respectively]. Tumor size more than 2 cm was significantly associated with LN metastasis (OR, 14.056; 95% CI, 1.76-112.267). The incidence of LN metastasis gradually increased from 3.2 to 20%, as number of risk factors increased (P = 0.019). LN metastasis was present primarily along the perigastric area in all except two patients (1.4%) with skip metastasis to extragastric area.
CONCLUSIONS: Standard surgery with at least D1 + LN dissection must be recommended for patients who proved to have risk factors for LN metastasis after ER, because the potential of skip metastasis is not negligible. Nevertheless, the minimal LN dissection, such as sentinel basin dissection, might be applied cautiously in patients with small-sized tumors after ER.