The use of one step nucleic-acid amplification (OSNA) in clinical practice: A single-centre study

Background: The development of intraoperative sentinel node biopsy (SLNB) analysis methods, such as One-Step Nucleic Acid Amplification (OSNA), has made single-stage procedures possible. Aims: We investigated the incidence of OSNA-detected lymph node positivity, comparing it to conventional histopathology, the incidence of non-SLNB node disease for the OSNA positive patients, and the breast re-operation rate, to assess the benefit from single-stage procedures. Methods: This was a single-centre series of 573 consecutive patients undergoing SLNB (173 histopathology and 400 OSNA). Results: OSNA-detected SLNB macrometastasis was similar to routine histopathology, with more micrometastasis detected (p < 0.001). Non-SLNB involvement in the OSNA group was similar to documented histopathological series. 27.6% of OSNA patients avoided further surgery because of OSNA. The median time for OSNA results was 42 min. Conclusions: OSNA is an effective method for detecting SLNB-metastasis. It is easily used in clinical practice, providing reliable results and negating the need for a second axillary operation. (C) 2012 Published by Elsevier Ltd.