sidered to improve postoperative survival [1][2][3]. A recent trend in the treatment of early gastric cancer, however, involves less invasive or limited surgery to improve the patient's quality of life [4][5][6]. Recent investigations have reported that micrometastases to lymph nodes that were overlooked by ordinary hematoxylin and eosin (H&E) staining could be detected by cytokeratin (CK) immunostaining, and these so-called micrometastases were found to have prognostic significance [7][8][9][10]. Mucosal gastric cancer (m-cancer) has been the prime candidate for less invasive surgery or endoscopic mucosal resection (EMR) [11,12]. However, the frequency or outcome of occult involvement in lymph nodes from m-cancer remains unclear. In this study, in order to assess the critical indications for EMR or less invasive surgery for m-cancer, we investigated the incidence of micrometastasis in lymph nodes in mcancer, using CK immunostaining.
Patients and methodsA total of 84 patients (46 men and 38 women) with mcancer, who underwent curative gastrectomy combined with lymphadenectomy at our hospital between 1986 and 1991, were investigated. The patients ranged in age from 37 to 82 years, with a mean age of 63 years. Total gastrectomy was performed in 6 patients (7%), and distal and proximal subtotal gastrectomies in 71 patients (85%) and 7 patients (8%), respectively. Fifty-eight patients underwent standard D2 lymphadenectomy. D2 plus part of group 3 lymph node dissections (lymph nodes in the hepatoduodenal ligament, around the common hepatic artery, behind the head of the pancreas, or at the root of the mesentery) were performed in 26 patients. All of the patients were followed-up for more than 5 years after surgery.Clinicopathologic data were evaluated according to the General rules for gastric cancer study in surgery and Abstract Background. Endoscopic mucosal resection is frequently used in the treatment of mucosal gastric cancer. Micrometastasis in the lymph nodes of mucosal gastric cancer remains unclear. Methods. We examined 2526 lymph nodes from 84 patients with mucosal gastric cancer. Two consecutive sections were prepared, for simultaneous staining with hematoxylin and eosin and immunostaining with CAM 5.2 monoclonal antibody against cytokeratin (CK), respectively. A clinicopathological comparison was made between patients with and without lymph node involvement. Results. Lymph node involvement was detected in 45 of 2526 (1.8%) lymph nodes. The incidence of nodal involvement was significantly increased, from 1.2% (1/84 patients) with hematoxylin and eosin staining, to 19% (16/84 patients) with CK immunostaining. Although no significant difference was found, micrometastasis to lymph nodes was more frequently detected in tumors larger than 1.0 cm (15/72 patients, 21%) than in those less than or equal to 1.0 cm (1/12 patients; 8%, P ؍ 0.307). However, discrete CK-positive cancer cells or clusters of CK-positive cancer cells were detected only in tumors larger than 2 cm. Conclusion. Because mucosal gastric cancer...
