Diagnosis comparison of intraoperative imprint cytology and frozen section for sentinel lymph node metastasis in breast cancer

Abstract

Objective To evaluate whether intraoperative imprint cytology can be used as a diagnostic method of sentinel lymph node metastasis for breast cancer patients in China. Methods A total of 154 breast cancer patients diagnosed histologically as ductal carcinoma in situ or T1-3N0M0 invasive breast cancer who underwent intraoperative sentinel lymph node biopsy from July 2012 to August 2015 in Shanxi Dayi Hospital were enrolled. The sentinel lymph node was detected by using standard dual tracer method. Intraoperative diagnosis was performed with imprint cytology as well as frozen section, and the final diagnosis was assessed by using paraffin pathology after surgery. Results The area under the receiver operator characteristic curve (AUC) for the diagnosis of sentinel lymph node metastasis by intraoperative frozen section and imprint cytology was 0.854 and 0.755, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of imprint cytology were 52.1% (25/48), 99.1% (105/106), 96.2% (25/26), 82.0% (105/128), 84.4% (130/154) respectively, and the corresponding diameters of frozen section were 70.8% (34/48), 100.0% (106/106), 100.0% (34/34), 88.3% (106/120), 90.9% (140/154) respectively. There was no statistically significant difference between the two groups (P > 0.05). The frozen section result was highly consistent with paraffin pathology, with a Kappa value of 0.769 8; while the Kappa value of imprint cytology was 0.587 4, which was moderately consistent with paraffin pathology. Conclusions There is no significant difference between imprint cytology and frozen section in the intraoperative diagnosis of sentinel lymph node metastasis. The consistency between frozen section and paraffin pathology is high. After standardized operations and professional training, imprint cytology can be considered as a substitute of intraoperative sentinel lymph node diagnosis in breast cancer patients. Key words: Breast neoplasms; Sentinel lymph node biopsy; Frozen section; Imprint cytology