J Korean Breast Cancer Soc.  2001 Dec;4(2):120-127. 10.4048/jkbcs.2001.4.2.120.

Micrometastasis of Sentinel Lymph Node in Breast Cancer

• Choi UJ
• Park WC
• Lee KM
• Yoon KJ

• KMID: 2173594
• DOI: http://doi.org/10.4048/jkbcs.2001.4.2.120

Abstract

PURPOSE: Sentinel lymph node (SLN) biopsy is thought to be a highly accurate method of assessing axillary nodal status in breast cancer. Furthermore, it can improve axillary staging by providing a more detailed examination of selected lymph nodes with a high probability of metastasis rather than the entire axillary nodes. The purpose of this study was to assess the incidence of SLN micrometastasis in node-negative breast cancer.
METHODS
SLN biopsy was performed in 40 patients with clinically node-negative breast cancer using vital blue dye and/or radioisotope methods; the blue dye method was used in 21 cases, the isotope method in 14 cases, and a combination of both methods in 5 cases. All lymph nodes were evaluated by routine pathologic examination, and a more detailed examination was performed on sentinel nodes in node-negative cases; sentinel nodes were serially sectioned at an interval of 40micrometer depth followed by H&E and cytokeratin immunohistochemical (IHC) staining.
RESULTS
Sentinel nodes were detected in 35 of 40 patients (87.5%). The mapping technique used in the remaining 5 cases was vital blue dye method only. Axillary node metastasis was found in 16 of 40 patients. Sentinel node biopsy accurately reflected the axillary node status in all cases; the sensitivity, specificity, and overall accuracy were 100, 100 and 100%, respectively. In 11 of 16 node-positive patients (68.8%), sentinel nodes were the only metastatic nodes. Occult micrometastases were found in SLN by serial section and IHC staining in 4 of 19 patients diagnosed as node- negative by routine pathological examination (21.1%). Occult micrometastasis of SLN was not correlated with primary tumor size, histologic grade or lymphovascular invasion with the exception of the S-phase fraction (P=0.023).
CONCLUSION
SLN biopsy was a highly accurate method of assessing axillary node metastasis in breast cancer. Serial sectioning and IHC staining of SLN were sensitive methods in the detection of occult lymph node metastasis.

Keyword

Breast cancer; Sentinel lymph node; Occult mir crometastasis

MeSH Terms

Biopsy
Breast Neoplasms*
Breast*
Humans
Incidence
Keratins
Lymph Nodes*
Neoplasm Metastasis
Neoplasm Micrometastasis*
Sensitivity and Specificity
Keratins