Background: Intraoperative touch imprint cytology (ITIC) is used for intraoperative detection of sentinel lymph node (SLN) metastases with intention to spare the patients another surgery. However, ITIC prolongs surgery, and ads costs. It is less likely positive in breast cancer (BC) patients after neoadjuvant chemotherapy (NAC) due to low axillary tumor burden. We aimed to evaluate ITIC in patients after NAC and assess how often it changes the ongoing surgery.
Materials and methods: BC patients treated with NAC followed by surgery at the Institute of Oncology Ljubljana, Slovenia, from January 2008 to July 2020 with ITIC performed were selected for analysis. Sensitivity, specificity, and the proportion of positive ITIC were calculated for different subgroups.
Results: Overall, 144 patients were identified. 73 of 144 (50.7%) patients were N0 before NAC and 71 of 144 (49.3%) were initially N1 and downstaged to N0 after NAC. ITIC was positive in 30 of 144 (20.8%) of patients, 7 of 73 (9.6%) in N0 group and 23 of 71 (32.4%) in N1 group. In N0 group, ITIC was positive in 1 of 20 (5%) if the tumor size was ≤ 20 mm after NAC, and 2 of 39 (5.1%) if the tumor was triple negative (TN) or Her-2+. In the N1 group ITIC was positive in > 20% in all subgroups. The sensitivity and specificity of ITIC was 50.8% and 100%, respectively and did not differ between groups.
Conclusion: ITIC after NAC is accurate with comparable sensitivity to ITIC in upfront surgery. We suggest omission of ITIC after NAC in initially N0 patients, particularly for tumors ≤ 20 mm after NAC, and in TN or Her-2+ subtypes.
Keywords: Axillary staging; Breast surgery; Intraoperative metastases detection; Neoadjuvant chemotherapy; Sentinel lymph node.
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