Utility of GATA-3 immunocytochemistry for the assessment of fine-needle aspiration in breast cancer patients with suspicious axillary lymph nodes at ultrasound.

ABSTRACT

BACKGROUND: Ultrasound-guided fine-needle aspiration cytology (FNAC) is a routine preoperative method for evaluating suspicious axillary lymph nodes (ALNs) in patients with breast cancer. However, a range of reasons such as morphological pitfalls, technical artifacts, and sampling errors restrict the sensitivity and accuracy of FNAC. This retrospective study investigated the diagnostic value of GATA-binding protein 3 (GATA-3) immunocytochemistry for FNAC. METHODS: Breast cancer patients who underwent preoperative FNAC for suspicious ALNs, relevant GATA-3 immunocytochemistry, and postoperative status of ALNs were reviewed from the period of March 2020 to February 2022. Altogether, 102 patients were included in the study. FNAC material smears stained with hematoxylin and eosin was initially assessed by two cytopathologists and categorized into five groups nondiagnostic, negative, atypical, suspicious, and positive for malignancy. Only group of cells positive for malignancy was considered positive. For each case, two selected slides were digitized (whole slide imaged) at ×40 magnification and decolored for GATA-3 immunocytochemistry. The expression of GATA-3 was scored ranging from 0 to 9 (Score ≥3 Positive, Score ≤2 Negative). If either FNAC or GATA-3 immunocytochemistry was positive or the combined test positive, then the case was considered positive. The sensitivity, specificity, and accuracy of FNAC, GATA-3 immunocytochemistry, and combined FNAC/GATA-3 immunocytochemistry were analyzed by χ2 and Fisher's tests. RESULTS: The mean age of the study participants was 50.62 (ranging 30-73 years). Invasive breast carcinoma (not otherwise specified) accounted for most histological subtypes, and grade 2 was the leading Nottingham grade. Sixteen cases directly underwent mastectomy while the other 86 patients had neoadjuvant therapy. A more serious diagnosis was made based on GATA-3 detection in 22.5% (n = 23) of 102 cases. Of the 23 cases, metastasis was confirmed by GATA-3 detection in 21 cases, and an uncertain diagnosis was ascertained based on GATA-3 immunocytochemistry in 2 with nondiagnostic FNAC results. The sensitivity (77/87, 88.5%) of GATA-3 detection for distinguishing malignancies from benign lesions was higher than that of FNAC alone (62/87, 71.3%) (p < .05). CONCLUSIONS: GATA-3 immunocytochemistry exhibited high diagnostic efficacy in distinguishing malignant breast cancer cells. Moreover, combined FNAC and GATA-3 immunocytochemistry achieved optimal results in terms of reducing the false-negative rate and promoting accuracy.