Immunohistochemical evaluation of lymph node micrometastases from breast cancer.

The lymph node micrometastasis was retrospectively immunohistochemically investigated in 185 patients with node-negative breast cancer and compared with the routine conventional findings. The monoclonal antibodies to epithelial membrane antigen (EMA) and mucinous-like carcinoma antigen (MCA) were used. Of 19 EMA-positive cases, 16 were false positive. Therefore only 3 cases were found to show staining with both EMA and MCA. The patients are all living and well and free of recurrence. No micrometastasis was immunhistochemically demonstrated in 11 node-negative breast cancer patients with subsequent metastases. The results of the present study indicate that the detection rate containing occult cells afforded by conventional routine evaluation is sufficient, at least in Japanese.