Background: The endoscopic resection of early gastric cancers (EGC) is a standard technique in Japan and is increasingly used throughout the world. Further experience in the treatment of EGC and a clearer delineation of the factors related to lymph-node metastasis would permit a more accurate assessment of endoscopic resection.
Methods: The study group comprised 1,389 patients with EGC who underwent gastrectomy with lymph-node dissection. We evaluated the relations of lymph-node metastasis to clinicopathological factors.
Results: Of the 718 patients with intramucosal carcinomas, 14 (1.9%) had lymph-node metastasis. All cases of lymph-node metastasis were associated with ulceration. No lymph-node metastasis was found in patients with intramucosal carcinomas without ulceration, irrespective of tumor size and histological type. Lymph-node metastasis was present in 14 (4.7%) of the 296 patients who had cancer with a submucosal invasion depth of less than 500 microm (sm1). Significantly increased rates of lymph-node metastasis were associated with undifferentiated types, ulcerated lesions and lymphatic invasion. No lymph-node metastasis was found in patients with differentiated sm1 carcinomas 30 mm or less in diameter without ulceration. Lymph-node metastasis occurred in 29% of the patients who had cancer with a submucosal invasion depth of 500 microm or more (sm2).
Conclusion: This large series of patients with EGC provides further evidence supporting the expansion of indications for endoscopic treatment, as well as warns against potential risks.