The significance of lymphonodal micrometastasis in the patients with gastric adenocarcinoma

Micrometastasis is defined as microscopical deposit of malignant cells, less than 2mm in diameter, separated from the primary tumor. This does not include discontinous growth in peritumoral region, but include microinolvement of regional lymph nodes. The literature on micrometastases, with special resperct to nodal micrometastasis, and their implications in gastric adenocarcinoma have been reviewed. Immunohistochemical detection offer the best accuracy for detection of nodal micrometastasis. Molecular techniques are more sensitive than method of immunohistochemical detection, but methods are compromised with false positive results caused by various sources of biological contamination. It is more than obvious that there is no definite agreement neither about risk factors, nor definitive clinical significance of micrometastatic node involvement in the patients with gastric adenocarcinoma. At present, the role of occult lymph node involvement proved its significance in two major fields: defining criteria for limited surgical dissection in the patients with early (sm) carcinoma in respect to detection of micrometastatic tissue in sentinel lymph node, and distinguishing the category of pN0 (Mi+) patients with potential benefit of postoperative adjuvant therapy.