Title: Immunohistochemical detection of lymph-node metastases
Abstract: R J Cote and colleagues (Sept 11, p 896)1Cote RJ Peterson HF Chaiwun B et al.Role of immunohistochemical detection of lymph-node metastases in management of breast cancer.Lancet. 1999; 354 (for the International Breast Cancer Study Group): 896-900Summary Full Text Full Text PDF PubMed Scopus (490) Google Scholar show the importance of immunohistochemistry for the detection of occult metastases in ipsilateral axillary lymph nodes in patients with breast cancer. Occult nodal metastases were detectable in 52 (7%) patients by serial haematoxylin and eosin sections and by immunohistochemistry in 148 (20%) patients.1Cote RJ Peterson HF Chaiwun B et al.Role of immunohistochemical detection of lymph-node metastases in management of breast cancer.Lancet. 1999; 354 (for the International Breast Cancer Study Group): 896-900Summary Full Text Full Text PDF PubMed Scopus (490) Google Scholar This study emphasises the need for accurate staging for patients with breast cancer since the detection of even small tumour-cell deposits is of prognostic importance. An average of 12 blocks per patient were scrutinised in this way, which is a labour intensive and costly procedure and may not be feasible in all pathology laboratories. In view of the fact that the sentinelnode biopsy predicts the absence of tumour cells in non-sentinel-node lymph nodes with high accuracy,2Borgstein PJ Pijpers R Comans EFI van Diest PJ Boom RP Meijer S Sentinel lymph node biopsy in breast cancer: guidelines and pitfalls of lymphoscintigraphy and gamma probe detection.J Am Coll Surg. 1998; 186: 275-283Summary Full Text Full Text PDF PubMed Scopus (678) Google Scholar one could well limit such intensive investigation of axillary lymph nodes to the sentinel node to arrive at an acceptable workload for the pathologists. We have investigated 250 breast-cancer patients by our protocol,3van Diest PJ Peterse HL Borgstein PJ Hoekstra O Meijer CJLM Pathologic investigation of sentinel lymph nodes.Eur J Nucl Med. 1999; 26: A49Google Scholar which includes step sectioning and CAM 5·2 immunohistochemistry at five levels with an interval of 250 μm, and ensures sampling through a large part of the sentinel node. 105 sentinel nodes were tumour positive in 84 patients. The number of positive sentinel nodes in the haematoxylin and eosin sections increased from 86 (81%), 90 (86%), 91 (87%), 95 (90%), to 95 (90%) from level one to level five. With immunohistochemistry the number of positive sentinel nodes increased from 91 (87%), 96 (91%), 99 (94%), 104 (99%), to 105 (100%) from level one to level five. This increase shows the value of multiple-level immunohistochemistry for detection of sentinel-node metastases of patients with breast cancer. Finding small metastatic deposits is worthwhile, since some of these patients have second-echelon metastases on subsequent axillary lymph-node dissection. There is a similar sensitivity for finding metastases as for intensive investigation of all axillary lymph nodes, because non-sentinel-node axillary lymph nodes rarely show metastases when the sentinel node is tumour negative by the described procedure.4Turner RR Ollila DW Krasne DL Giuliano AE Histopathologic validation of the sentinel lymph node hypothesis for breast carcinoma.Ann Surg. 1997; 226: 271-278Crossref PubMed Scopus (596) Google Scholar We have shown that immunohistochemical examination should not be limited to one single section, as Cote and colleagues propose, since immunohistochemistry of multiple sections increases the detection rate of occult nodal metastases even further. Because this intensive work-up can be limited to the sentinel node, this would be an acceptable workload for the pathologist.