Intraoperative determination of axillary node metastasis by RT-PCR

The intraoperative determination of axillary node micrometastasis according to the Rapid GeneSearch(TM) Breast Lymph Node (BLN) is based on RT-PCR (mRNA of mammaglobine and CK19) detects metastases > 0.2 mm. Patients and methods. Eighty-three pts between November 2007 and June 2008 were included (33 from Centre Jean-Perrin and 50 from Centre Oscar-Lambret). Lymph nodes were cut in 2 mm slices, and 1 out of 2 was examined with BLN; the others were examined by imprints then histological exam with immunohistochemistry. Results. Forteen pts had micro-or macrometastasis. Seven were positive with intraoperative imprints including six macrometastasis and one micrometastasis; seven were positive with BLN and seven at histological exam with two cases of discordance. Sensitivity was 92%, specificity 98%. Positive predictive value 92%, and negative predictive value 98%. The median time for intraoperative determination was 40 minutes for 2 SLN. Discussion. Half each lymph node is study by each method. This explains the discordances observed. Limit of BLN is the absence of CTI detection; however there is no consensus about the necessity of axillary clearance in such a case. Conclusion. In this series BLN reduces axillary clearance and improves comfort patients.