The evaluation and optimization of intraoperative touch imprint cytology for sentinel lymph nodes in early-stage breast cancer in China

Abstract

Background: Accurate intraoperative diagnosis of sentinel lymph node (SLN) metastasis reduces the need for additional surgery in patients with involved nodes. The present study evaluates the clinical value of multiple cross-sectional touch imprint cytology (TIC) as an intraoperative assessment for the diagnosis of SLN metastasis.

Methods: This study consisted of 366 patients with surgically harvested SLNs that were sliced along their long axis at 2.0-3.0-mm intervals and 122 patients with SLNs that were sliced along their short axis at 1.5-mm intervals using a cutting apparatus designed by our group. The first group of patients was enrolled in this study between February 2005 and February 2008, while the second group was enrolled between March 2008 and January 2009. Serial sectioning of the SLNs at 100-microm intervals with hematoxylin-eosin (H&E) staining was used as the gold standard for pathological diagnosis.

Results: Multiple cross-sectional TIC has a sensitivity, specificity, and overall accuracy rate of 92.0, 99.0, and 97.5%, respectively, on a per-patient basis, and it is superior to the standard imprint preparation protocol. Furthermore, the multiple cross-sectional TIC technique developed in this study was observed to detect more accurately macrometastases on a per-patient basis in comparison to the typical protocol (P = 0.023). Of the patients included in this study, 97.7% had a positive SLN within their first three harvested SLNs.

Conclusions: Multiple cross-sectional TIC is superior to the standard protocol, especially due to its ability to locate macrometastasis. Limiting intraoperative TIC to the first three harvested SLNs in the diagnosis of SLN metastasis may make this diagnostic procedure significantly cheaper and easier for pathologists to perform.