Prognostic significance of perirectal lymph node micrometastases in Dukes'B rectal carcinoma: An immunohistochemical study by CAM5.2

Lymph node metastasis is an important prognostic factor for rectal carcinom a, but only a few attempts at defining the relationship between lymph node micrometastases and prognosis have been made, The purpose of this study was to examine the correlation between the presence of micrometastases and pro gnosis in patients with rectal carcinoma. Six hundred forty-four lymph node s were dissected from 42 patients with Dukes' B rectal carcinoma and staine d immunohistochemically using a monoclonal antibody, CAM5.2, that binds cyt okeratin, Clinicopathological factors, rate of recurrence, and prognosis we re compared among patients with and without micrometastases, Micrometastase s were detected in 19 lymph nodes (19 of 644 = 2.9%) from 9 patients (9 of 42 = 21.4%), The presence of micrometastases was not related to clinicopath ological factors, There were significant differences in recurrence rates (5 of 9 versus 5 of 33, P = 0.02), relapse-free survival rates (P = 0.04), an d 10-year survival rates (P = 0.03) between patients with and without micro metastases. Immunohistochemistry successfully identified micrometastatic fo ci in lymph nodes missed with conventional staining methods, The existence of micrometastases influenced the prognosis in patients with Dukes' B recta l carcinoma.