Comparison of one-step nucleic acid amplification (OSNA) method and routine histological investigation for intraoperative detection of lymph node metastasis in Polish women with breast cancer.

Sentinel lymph node (SLN) biopsy is a part of the staging procedure in breast cancer patients. Intraoperative molecular analysis for SLN metastases using the one-step nucleic acid amplification (OSNA) method based on reverse-transcription loop-mediated amplification (RT-LAMP) has already been validated in breast cancer. In this study, we compare the intraoperative OSNA method to our routine histological investigation. To evaluate the performance of OSNA in comparison to histology, analysis of 74 SLN from 60 breast cancer patients was conducted with both methods. Of the 22 histologically positive samples, 14 were attributed to macrometastases (++) in the OSNA-CK19 assay and 8 to micrometastases (+). Two samples negative in histopathology were positive in the OSNA method (micrometastases +). Our results show that OSNA is an excellent method for the detection of metastases in lymph nodes and can be applied as an intraoperative diagnostic approach. Intraoperative molecular analysis for SLN metastases using the OSNA method reduces the number of admission days and duration of surgery. To our knowledge this is the first study referring to Polish women.