Less operations required due to perioperative frozen section examination of sentinel nodes in 275 breast cancer patients

OBJECTIVE: To determine the reliability of a peroperative frozen section examinations of sentinel lymph nodes in mammary carcinoma. DESIGN: Retrospective. METHOD: In the Reinier de Graaf Hospital and Diagnostic Centre SSDZ Delft, the Netherlands, the results of frozen section from sentinel lymph node investigations of mammary carcinomas from 1997-2000 were compared with the final pathological results. If axillary dissection had been performed on these patients, the histopathological findings of the dissected lymph nodes were also studied. RESULTS: Frozen sections were made of 287 sentinel lymph nodes from 275 patients. A tumour was found in the sentinel lymph nodes of 64 patients and these patients immediately underwent a complete axillary lymph node dissection. For 31 of these patients a tumour was also found in the other lymph nodes. In 29 of these 31 patients, histological examination had shown extranodal extension. The frozen sections from the sentinel nodes of the remaining 211 patients were considered negative. However, in 13 of these patients, the paraffin sections of the sentinel node nevertheless showed a tumour and the remaining axillary lymph nodes were removed in a second operation. In the last 89 patients studied, the sentinel lymph nodes were cut at four levels and stained immunohistochemically at one level for cytokeratins. Accordingly micrometastases were found in the sentinel lymph nodes of 4 of the 13 patients with (false-)negative frozen sections. False-positive results did not occur. CONCLUSION: The major advantage of the sentinel node method in breast cancer is that for women without metastasis present in the sentinel node, axillary dissection is avoided. By means of a peroperative examination of frozen sections, 83% of the patients with a metastasis in the sentinel lymph node (or about one quarter of all patients) were spared from having a second operation for axillary dissection at a later stage.