Intraoperative Touch Imprint Cytology in Targeted Axillary Dissection After Neoadjuvant Chemotherapy for Breast Cancer Patients with Initial Axillary Metastasis.

BACKGROUND: For breast cancer patients, a false-negative rate lower than 10% can be achieved if targeted axillary dissection (TAD) is performed, which includes the excision of both biopsy-proven positive lymph nodes (BxLNs) and sentinel lymph nodes (SLNs). However, little evidence exists on the accuracy of intraoperative touch imprint cytology (ITPC) applied in TAD after neoadjuvant chemotherapy (NAC) for breast cancer patients with initial axillary metastasis. This study aimed to investigate the accuracy of ITPC in TAD after NAC.

METHODS: Breast cancer patients with biopsy-confirmed nodal metastasis were prospectively enrolled in the study. After completion of NAC, all patients underwent TAD followed by axillary lymph node dissection (ALND). Then ITPC was performed to evaluate BxLNs and SLNs. The accuracy of TAD and ITPC was calculated in comparison with hematoxylin and eosin (H&E) staining of ALNs. The results of ITPC during 6 months at our center in the adjuvant setting were used for comparison .

RESULTS: Overall, the false-negative rate of TAD was 10.8%. In a test with 92 patients, ITPC had an accuracy of 92.4%, a sensitivity of 87.9%, and a specificity of 94.9%. In the non-NAC group, ITPC showed similar accuracy (91.2%) and specificity (97.9%) but significantly lower sensitivity (68.9%; P = 0.03).

CONCLUSIONS: The use of ITPC was feasible for TAD among breast cancer patients with biopsy-confirmed axillary metastasis who were treated with NAC. All the misses in the ITPC involved patients with micrometastases or isolated tumor cells. Use of ITPC can help decrease the number of second operations for patients with residual disease in ALNs after NAC.