Abstract PO4-22-10: Prognostic impact of preoperative lymph node diagnostic tools for patients with suspicious node positive breast cancer

Abstract

Abstract (Abstract) Recently, the SOUND trial demonstrated the feasibility for omission of sentinel lymph node biopsy (SNB) in cases with negative ultrasound (US)-guided fine-needle aspiration cytology (FNA) of suspicious lymph nodes (LNs). An important consideration for omission of SNB depends on a highly accurate assessment of preoperative staging for axillary LNs. (Purpose) The purpose of this study was to investigate the impact of preoperative diagnostic tools for axillary lymph nodes (LNs) staging of early breast cancer. (Materials and Methods) A total of 3088 consecutive patients with operable breast cancer were retrospectively identified at our institution between April 2013 and March 2020. Patients with suspicious axillary LN of breast cancer were assessed using preoperative US and computed tomography (CT), underwent FNA or core needle biopsy (CNB). The inclusion criteria for both FNA and CNB were a cortical thickness [3 mm or abnormal morphological characteristics. Patients with biopsy-proven metastasis underwent axillary lymph node dissection (ALND), and those with a negative FNA or CNB underwent SNB. If the SNB was positive, ALND was performed. Diagnostic accuracy for SNB was calculated for both FNA and CNB. In addition, the patients in this study were divided into two groups as follows: the cN0-FNA negative group (suspicious LN but negative FNA) and the cN0-CNB group (suspicious LN but negative CNB). Overall survival (OS)and invasive disease survival(iDFS) was estimated by using the Kaplan-Meier method and compared by using the log-rank test. (Results) A number of patients with negative or suspicious metastasis US/CT findings of LNs were 3187, with 963 undergoing FNA and 395 undergoing CNB for suspicious LNs. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 63, 99, 99, 73, and 81% in FNA, and 87, 100, 100, 91 and 95% in CNB, respectively. SNB was performed in 207 (cN0-CNB group) of 395 CNB and 581 (cN0-FNA group) of 963 FNA patients. Two hundred and seven patients from the cN0-CNB group (T1ab; 42, T1c; 72, T2;84, T3;9 patients) treated with SNB were compared to 581 from the cN0-FNA group (T1ab;86, T1c;193, T2;278, T3;24 patients) in terms of number of LN metastasis. A number of patients with micrometastases, 1,2,3 or more than 4 positive LNs were 5(2%),7(3%),3(1%)9,3(1%) and 0 (0%) in cN0-CNB group, and 23(4%),67(12%),26(4%),12(2%) and 29 (5%) in cN0-FNA group, respectively. The significant difference in 5ys iDFS and OS was observed between CNB group and FNA group (94.2% vs.91.4%, p =0.04 and 99% vs. 95%, p=0.004, respectively). Conclusions The preoperative diagnosis of axillary LNs was influenced by the diagnostic tool used. CNB is a reliable method for the preoperative diagnosis of LN metastasis. The prognosis of early breast cancer with clinically metastasis-negative lymph nodes diagnosed by CNB is better than that by FNA. Table. Number of positive lymph nodes cN0-FNA (%) cN0-CNB (%) Total 207 100 581 100 0 189 91 424 73 micrometastasis 5 2 23 4 1 7 3 67 12 2 3 1 26 4 3 3 1 12 2 4 more than 0 0 29 5 Citation Format: Rikiya Nakamura, Shouko Hayama, Rikiya Nakamura, Naohito Yamamoto. Prognostic impact of preoperative lymph node diagnostic tools for patients with suspicious node positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-22-10.