284P - Advantages of one step nucleic acid amplification (OSNA) whole node assay in sentinel lymph node (SLN) analysis in breast cancer
|Date||01 October 2012|
|Event||ESMO Congress 2012|
|Session||Poster presentation III|
|Topics|| Breast Cancer, Early Stage
A. Santaballa1, H. De La Cueva2, C. Salvador2, A. Garcia Martinez3, M.J. Guarin3, D. Lorente2, L. Palomar2, I. Aznar4, F. Dobon4, P. Bello5
The aim of this study is to present our first results with OSNA assays performed in a routine clinical setting in 168 patients with invasive and in situ breast cancer and compare them with conventional histopathology results for SLN biopsies in a historical cohort in our institution.Methods
412 patients (total study population) with clinically node negative early stage breast cancer underwent an axillary SLN in our institution. The SLN was assesed with OSNA in 168 patients. The OSNA results were compared with conventional histopathology results from 244 patients who has undergone a SLN biopsy few years earlier. Patients characteristics were evaluated in both groups and the rate of metastases detected by both methods and the surgical procedures were compared.
|Characteristics||OSNA Cohort (n = 168)||Historical cohort (n = 244)|
|Age, median (range)||58 (33-86)||57 (30-93)|
|Tumor size, mean (range) mm||16.63 (2-60)||14.16 (2-55)|
|Other subtypes invasive||8||19|
|Ki 67||≤ 10%||72||95|
SLN metastasis were found in 45 patientes in the OSNA group and in 49 in the historical group. There were no differences in rates of macrometastases (27 by OSNA, 41 by HE) and we found differences in micrometastasis rate (18 by OSNA and 8 by HE p =0.007). Axillary node dissection (ALND) was performed in 45 patients in the OSNA group and in 49 in the historical group. All the patients diagnosed by OSNA had a complete ALND during the initial surgical procedure. In the historical cohort the ALND was performed during the initial surgical procedure in 41 patients, and ALND was performed in a second surgical procedure in 8 patients.Conclusions
The OSNA assay can detect SLN metastasis as accurately as conventional pathology with increased detection of micrometastasis. The second surgery can be reduced with the OSNA assay.Disclosure
All authors have declared no conflicts of interest.