Clinical implications of lymph node micrometastases in patients with colorectal cancers - A case control study

There is no unanimity about the prognostic significance of lymph node micro metastases from colorectal cancer. A case-control study of patients with re current and nonrecurrent colorectal cancer who were closely matched for the Dukes stage, extent of lymph node dissection, tumor size, tumor location, number of resected lymph nodes, age and gender was performed. The presence of micrometastases in a total of 1,633 lymph nodes from 44 patients (22 wit h and 22 without recurrence) were examined by immunohistochemistry using an tibodies for cytokeratin (KL-1) and p53 (RSP53). Immunostaining with KL-1 r evealed micrometastases in 15/22 patients [68%; 82/820 lymph nodes (10%)] a nd 15/22 patients [68%; 45/813 lymph nodes (6%)] in the recurrent and nonre current groups, respectively. Immunohistochemical analysis, using RSP53, of 18 paired patients with p53-positive primary tumor revealed micrometastase s in 4/9 patients [44%; (7/265 lymph nodes (2.6%)] and 4/9 patients [44%; 6 /257 lymph nodes (2.3%)] with and without recurrence, respectively. Neither the micrometastatic frequencies of the patients nor the resected lymph nod es of the recurrent and nonrecurrent groups differed significantly. Microme tastases in regional lymph nodes are an interesting phenomenon, but do not influence patients' prognoses if the involved lymph nodes are removed. Copy right (C) 1999 S. Karger AG, Basel.