Occult regional lymph node metastases from breast carcinoma: immunohistological detection with antibodies CAM 5.2 and NCRC-11.

Ninety-eight consecutive patients with primary operable breast cancer and an initial diagnosis of no regional lymph node metastases as assessed by conventional light microscopy were studied. Immunohistological staining of routine lymph node sections was assessed using two monoclonal antibodies: CAM 5.2 (Becton Dickinson) with specificity for low molecular weight cytokeratin, and NCRC-11 (CRC Laboratories, Nottingham) with specificity for epithelial mucin antigen. Positive staining for occult metastases was seen in nine patients with CAM 5.2 and in eight of these nine with NCRC-11. At a follow-up out to 14 years, there was no difference in overall survival, in recurrence-free survival, or in frequency of or time to presentation of local or regional recurrences between occult metastasis-positive and occult metastasis-negative patients. This study concludes that while immunohistological staining of routine lymph node sections increases the diagnostic yield of metastases, it is not to be recommended as this increase is of no useful clinical value.