Can Axillary Lymph Node Status in Breast Cancer Patients be Improved by Immunohistochemistry?

Relevance of axillary lymph node (LN) status in breast cancer patients has decreased since (1) more and more patients are diagnosed at an early stage with small tumors without LN involvement and (2) criteria for giving adjuvant therapy are not strictly related to LN status anymore. We investigated whether prognostic relevance of LN status can be improved by staining lymph nodes immunohistochemically in order to detect micrometastases previously not seen by H + E sectioning. Lymph nodes of 212 breast cancer patients considered to be negative by multilevel H + E histopathological sectioning were immunohistochemically re-evaluated using anti-cytokeratin antibodies. All sections were analyzed by the same pathologist (MM). Disease free and overall survival were analyzed for up to 10 years after surgery, median follow-up of 4.2 years. Immunohistochemical examination of 'negative' lymph nodes revealed epithelial cells not seen in H + E sectioning in 14 (7%) cases. A difference in overall or disease free survival between patients with or without epithelial cells in lymph nodes was not observed. Although immunohistochemical detection of single tumor cells in lymph nodes may be useful in a sentinel LN setting it does not add relevant information beyond H + E analysis if multilevel sectioning is performed. The majority of breast cancer patients presents with negative lymph nodes to date and does not benefit from axillary dissection but may suffer long-term side effects. Therefore it has to be questioned, whether or not axillary lymph node dissection can be substituted in certain subgroups of patients by other procedures like bone marrow biopsy.