Background: Endoscopic resection (ER) is an effective treatment for early gastric cancer (EGC) without lymph node metastasis. However, after ER additional surgery may be needed to manage the risks presented by residual cancer or lymph node metastasis.
Methods: ER was performed on 344 gastric adenocarcinomas between November 2001 and April 2006 at the Korean National Cancer Center under the strict pre-procedural indication. The authors performed operations in 43 patients due to: residual mucosal cancer, a mucosal cancer larger than 3 cm, or a submucosal cancer regardless of size or margin involvement. ER and surgical specimens were reviewed and analyzed for residual cancer and lymph node metastasis.
Results: Based on examinations of ER specimens, cancer was confined to the mucosal layer in 15 patients (34.9%) and invaded the submucosal layer in 28 patients (65.1%). Surgical specimens showed residual cancer in 17 patients (39.5%) and lymph node metastasis in four (9.3%). Neither residual cancer nor lymph node metastasis was found in patients with less than 500 microm submucosal invasion without margin involvement in ER specimens. In three of four patients with lymph node metastasis, the depth of submucosal invasion was 500 microm or more; the remaining patient had a 4-cm-sized differentiated mucosal cancer.
Conclusions: When a pathologic evaluation of an ER specimen reveals more than 500 microm of submucosal invasion or a mucosal cancer of larger than 3 cm, surgery should be considered due to the risk of lymph node metastasis.