Detection of micro-metastasis using cytokeratins (AE1/AE3) in haematoxylin & eosin-stained N(0) lymph nodes of oral squamous cell carcinoma

BACKGROUND & OBJECTIVES: Oral squamous cell carcinoma (OSCC) is one of the most common malignancies affecting the head-and-neck region, regional lymph nodes being an important prognostication factor dictating the survival rate. Despite an array of modalities used, clinically, radiographically and routine histopathologically, the detection of micro-metastasis (2-3 mm tumour cell deposits) in the lymph nodes often escapes identification. The presence of few of these tumour epithelial cells in the lymph nodes drastically increases mortality and alters treatment plan. Hence, the identification of these cells is of major prognostic significance for a patient. Thus, the present study was aimed to evaluate and detect the efficacy of the immunohistochemical (IHC) marker [cytokeratin (CK) AE1/AE3] over routine Hematoxylin & eosin (H & E) staining in detecting micro-metastasis in the lymph nodes of OSCC cases. METHODS: Hundred H & E-stained N(0) lymph nodes of OSCC cases treated with radical neck dissection were subjected to IHC with marker AE1/AE3 antibody cocktail for detecting micro-metastasis. RESULTS: The IHC marker CK cocktail (AE1/AE3) did not demonstrate any positive reactivity for the target antigen in all the 100 H & E stained lymph node sections evaluated in the present study. INTERPRETATION & CONCLUSIONS: This study was undertaken to check the efficacy of IHC (CK cocktail AE1/AE3) in the detection of micro-metastasis in lymph nodes that are found to be negative in routine H&E stained sections. The findings of this study suggest that the IHC marker AE1/AE3 did not prove to be useful to detect micro-metastasis in this study population.