Laminin distribution patterns are closely related to liver metastasis in gastric cancer.

Laminin is the major glycoprotein of basement membrane and is known to have an important role in the metastatic process. The authors used immunohistochemical techniques to evaluate the distribution of laminin-containing basement membrane in specimens from 157 patients with advanced gastric cancer. This membrane was found less frequently in the deep periphery than in the mucosa. According to our classification of distribution patterns, 39 (24.8%) tumors had laminin in the mucosa and the deep periphery of tumor (Group A); 37 (23.6%) tumors had laminin in the mucosa but not in the periphery (Group B); and in 81 (51.6%) tumors laminin was not found in the mucosa or the periphery (Group C). Tumors with laminin in the deep periphery (Group A) were characterized by expansive growth (P < 0.05), and there was a significant correlation with the occurrence of vessel invasion (P < 0.05) and liver metastasis (P < 0.01). Patients with Group A tumors had poor prognosis compared with patients with Group C tumors (P < 0.05). Multivariate logistic regression analysis showed laminin distribution patterns to be an independent value for predicting liver metastasis, as are lymph node involvement and expansive growth. The authors propose that laminin-positive basement membrane in the deep periphery in gastric cancer tissue is a significant risk factor for liver metastasis. For such high-risk patients, close follow up and postoperative adjuvant therapy are required.