Aims Touch preparation (TP) and frozen section (FS) are the two methods routinely used in the intraoperative evaluation (IOE) of sentinel lymph nodes (SLNs) to detect metastases in patients with breast cancer. Both methods are extremely sensitive and specific in the primary surgery (non-neoadjuvant systemic therapy (non-NST)) setting. Since NST introduces unique challenges in the IOE of SLNs, the aim was to determine the accuracy of TP and FS in the IOE of SLNs in the NST setting and compare the results with the non-NST setting and to examine factors that contribute to any differences.
Methods We analysed 871 SLNs from 232 patients (615 SLNs from NST and 256 SLNs from non-NST settings) between 2016 through 2019.
Results In the NST group, TP alone (n=366) had a sensitivity of 45.7% and specificity of 99.7%; FS alone (n=90) had a sensitivity of 83.3% and specificity of 100%. When both TP and FS (n=135) were used, the sensitivity was 80.3% and the specificity was 98.6%.
In the non-NST group, TP alone (n=193) had a sensitivity of 66.7% and specificity of 100%; FS alone (n=22) had a sensitivity and specificity of 100%; and combined TP and FS (n=34) had a sensitivity and specificity of 100% and 96%, respectively.
Conclusions Evaluating SLNs intraoperatively in the NST setting can be challenging secondary to therapy-related changes. In the NST setting, FS has higher sensitivity and specificity compared with TP for the IOE of SLNs and should be the preferred method.
- Sentinel Lymph Node
- Breast Neoplasms
- Neoplasm Metastasis
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information. NA.
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Handling editor L C Collins.
Contributors Conception or design of the work: SS and HH. Data collection: MH-R, MM. Data analysis and interpretation: MH-R, CQ-V, MM. Drafting the article: MH-R, SS, HH, ML. Critical revision of the article: all authors. Final approval of the version to be published: all authors. SS is responsible for the overall content as the guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.