Background: Although the number of patients with early gastric cancer (EGC) treated by endoscopic mucosal resection (EMR) has increased, the appropriate strategy for treating those with incomplete resection has not been established.
Methods: This study analyzed 726 cases of EGC in patients treated by EMR between 1991 and 2000, in order to clarify the en-bloc and complete resection rates. We classified patients with incomplete resection into four groups according to the estimated risk of residual cancer or lymph node (LN) metastasis, determined from pathological findings of EMR specimens. We then analyzed 45 patients with EGC treated surgically after incomplete EMR, with the aim of eliciting the risk of residual cancer and LN metastasis.
Results: Of the 726 patients, 529 (72.9%) had an en-bloc resection, while 378 (52.1%) had a complete resection. Three hundred and nine patients were found to have mucosal cancer and lateral cut-end-positive status with no LN metastasis (group A). In this group, 18 patients (5.8%) had residual cancer, with the lesions in the majority of patients being limited to the mucosal layer. Group B consisted of 14 patients with differentiated and submucosal (sm1) depth cancers, with 1 patient having residual cancer and 2 patients having LN metastasis. Fifteen patients were classified as group C, with sm2 or greater and vertical cut end-negative status, with 2 showing residual cancer and 1 showing LN metastasis. Group D included 10 patients with vertical cut end-positive status. Four of these patients had residual cancer while 1 had LN metastasis.
Conclusion: We recommend that patients in group A should have close follow-up or endoscopic treatment, while those in groups B, C, or D should be treated by gastrectomy associated with LN dissection.