Intraoperative examination of sentinel lymph nodes by immunohistochemical staining in patients with breast cancer

Aim: To performed a prospective investigation of the relative merits of rapid cytokeratin immunohistochemical (CK-IHC) staining of the SLN removed during the operation of breast cancer patients. Study design: Between December 2002 and March 2004, 62 patients with T1 and T2 breast cancer were enrolled after undergoing successful sentinel lymph node biopsy. Eighty-nine sentinel lymph nodes (mean number, 1.44) were biopsied and first examined by hematoxylin-eosin (H&E) stained frozen section. All the tumour free sentinel lymph nodes by H&E stained frozen section were immunostained for cytokeratin using a rapid immunohistochemical assay (Cytokeratin (PAN), 1:50, Novocastra Lab., Newcastle, UK) during the operations. Results: Rapid IHC staining revealed seven positive sentinel lymph nodes that were negative for metastasis by H&E staining. This study showed a sensitivity of 92.86%, a specificity of 100%, an accuracy of 98.9%, and a negative predictive value of 98.7%. Conclusions: The intraoperative examination of sentinel lymph nodes is an accurate and effective way of predicting the axillary lymph node status of patients with breast cancers.