Evaluation of the histological size of the sentinel lymph node metastases using RT–PCR assay: a rapid tool to estimate the risk of non-sentinel lymph node invasion in patients with breast cancer
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A RT–PCR assay (GeneSearch™, Veridex, LLC), FDA approved and CE marked to detect metastases >0.2 mm in sentinel lymph nodes (SLNs) is used intra-operatively for the management of patients with breast cancer. The assay provides qualitative results by applying cut-off values to cycle times (Ct) for mammaglobin (MG) and cytokeratin-19 (CK19) genes. Aims of this study were to evaluate the performance of the quantitative Ct values to estimate the size of nodal metastases and the risk of additional disease in non-SLNs. SLNs from 367 patients were clinically processed using both BLN assay and post-operative histology. Complementary axillary lymph node dissection (ALND) was performed concurrently in case of BLN assay positivity or tumour size >2 cm. BLN positivity was reported in 19.6% of the patients for a sensitivity of 89%. BLN specificity (94.5%) and negative predictive value (97.5%) clearly demonstrated its reliability to guide ALND decision. All, except one, residual axillary metastases were found in BLN-positive patients. Considering the 78 patients with SLN positivity or discordant status according to both criteria, the metastases histological size was significantly correlated to the expression level of MG (ρ = 0.62) and CK19 (ρ = 0.64) genes (P < 10E-6). Moreover, ALND status positivity was significantly associated to Ct value of MG (z = 2.4; P = 0.018) and CK19 (z = 3.2; P = 0.001). The high intra-operative quality performance of the BLN assay minimizes the need for second surgeries for ALND. Results from this investigational study suggest that markers Ct value may provide, intra-operatively, valuable metastases size data and a risk prediction of additional disease in non-SLNs.
KeywordsBreast cancer Sentinel lymph node Molecular assay Nodal metastases size
The authors thank « Le Fond Heuson » and « Les Amis de L’Institut Jules Bordet » for financial support.
- 1.Martin Martinez MD, Veys I, Majjaj S, Lespagnard L, Schobbens JC, Rouas G, Filippov V, Noterman D, Hertens D, Feoli F, Bourgeois P, Durbecq V, Larsimont D, Nogaret JM (2009) Clinical validation of a molecular assay for intra-operative detection of metastases in breast sentinel lymph nodes. Eur J Surg Oncol 35(4):387–392PubMedGoogle Scholar
- 2.Veys I, Durbecq V, Majjaj S, Schobbens JC, Noterman D, Sirtaine N, Martinez MD, Hertens D, Feoli F, Bourgeois P, Nogaret JM, Larsimont D (2009) Eighteen months clinical experience with the GeneSearch breast lymph node assay. Am J Surg 198(2):203–209Google Scholar
- 7.American Joint Committee on Cancer (2002) Breast. AJCC cancer staging manual, 6th edn. Springer, New York, pp 221–240Google Scholar