Detection and significanec of micrometastases in regional lymph-bides ub dyjes'A,B rectal carcinoma

Objective To study micrometastases in lymph nodes in Dukes'A,B rectal carcinoma and its relevance to clinical pathology and prognosis.Methods A total of 183 peri-rectal lymph nodes from 57 patients with clinicopathologic Stages A and B were immunohistochemically stained with mouse monoclonal antibody against human cytokeratin 20 for micrometastic tumor cells.The results were analyzed statistically.Results Micrometastases were observed in 48 lymph nodes(26.2%) of 25 patients (43.9%).The presence of micrometastases was closely correlated with size,differentiation,location of primary tumor,but was not related to age,sex and invasion depth of primary tumor.With a median follow-up of 42 months,we found no difference in disease-free survival between the tumor cell negative and posttive groups.Conclusion The results show that occult tumor cells might increase the risk development of a local recurrence of the tumor and/or distant metastases but have no significance of prognosis statistically.