OBJECTIVETo evaluate the reliability and application of GeneSearch(TM) breast lymph node assay (Genesearch), a real-time fluorescence quatitative PCR method, in intraoperative assay of metastasis in sentinel lymph nodes (SLNs) from breast cancer patients.

METHODSTotally 140 SLNs from 80 patients with breast carcinoma were prospectively studied from May 2010 to August 2010. The 80 patients included 78 women and 2 men who ranged in age from 29 to 85 years, and the median age is 49 years. The expression of CK19 and mammaglobulin in all 140 SLNs were detected by Genesearch, and the results were compared with that of histological evaluation of both frozen and paraffin-embedded sections.

RESULTSAmong SLNs, by histological analyses, there were 121 without metastasis, 17 with macrometastasis, 2 with micrometastasis, and none of isolated tumor cell. By Genesearch, there were 119 without metastasis and 21 with metastasis. Genesearch showed sensitivity of 89.4%, positive predictive value of 81.0%, negative predictive value of 98.3% and specificity of 96.7% by comparing to histological analyses. The concordance between Genesearch and histological analysis was 95.7%. The sensitivity of Genesearch was 15/17 for macrometastasis and 2/2 for micrometastasis.

CONCLUSIONSGenesearch detection presents high sensitivity and specificity in evaluating metastasis of sentinel lymph nodes in breast cancer, but strict performance technically is necessary to avoid false positive and false negative results. Inability of further subtyping for the positive cases might be the key limitations for wide application of this method.