Clinicopathological features and overexpression of matrix metalloproteinases in intramucosal gastric carcinoma with lymph node metastasis

Endoscopic mucosal resection, which has been widely accepted for the treatm ent of intramucosal gastric carcinoma (IMGC) because of the minimal invasiv eness of the procedure and the sustained quality of Life it provides, can o nly be used on the premise that the carcinoma has no lymph node metastasis, We evaluated the clinicopathological and biological features of IMGC with lymph node metastases in relation to matrix metalloproteinase (MMP) express ion. Fifteen cases of lymph node metastasis-positive [n(+)] IMGC and 59 cas es of lymph node metastatic-negative [n(-)] IMGC were obtained. The express ion of MMP-2 and MMP-9 was investigated with immunohistochemical methods. C linicopathologically, n(+)-IMGCs were more likely to be of a larger size, t o be of poorly differentiated adenocarcinoma, to have had lymphatic permeat ion [ly(+)], and to have ulcerations within the lesion compared to n(-)-IMG Cs, The incidence of the positive expression of MMP-9 in n(+)-IMGCs (67%) o r ly(+)-IMGCs (86%) was significantly higher than that in n(-)-IMGCs (32%) or ly(-)-IMGCs (34%), Even in IMGCs, carcinoma cells may produce MMPs that can degrade the basement membrane, allowing them to permeate the lymph capi llary, Ulcerations within the lesion may also facilitate the interchange of lymphatic now between the mucosa and the submucosa, promoting the developm ent of lymph node metastases.