Abstract P2-01-18: Preoperative axillary imaging with ultrasonography: Among the breast cancer patients with lymph node metastases, can we identify the patients who may omit axillary dissection?

Abstract

Abstract (Introduction) ACOSOG Z11 and EORTC AMAROS showing little benefit to axillary dissection(ALND) for early stage breast cancers with limited nodal disease have led us to questioning the value of preoperative axillary imaging. It may not result in a benefit to the patients to perform ALND by diagnosing a few or small axillary lymph node(ALN) metastases preoperatively. (Aim) A purpose of this study is to determining the association between diagnostic method and metastatic number of ALN metastases, and to find the patients who can omit ALND safely even if with ALN metastases. (Methods)A database of consecutive primary breast cancer patients who underwent comlete ALND at our institution in 2008-2011 was analyzed. After we excluded patients treated with neoadjuvant systemic therapy, a total of 390 patients were included. By diagnostic methods of ALN metastases, we classified them in four groups as follows. Group A (n=41) : suspicious ALNs on axillary ultrasound(AUS) and ultrasound-guided fine needle aspiration cytology (FNAC) positive, Group B (n=47) : only one abnormal ALN on AUS +/- FNAC, Group C(n=53) : multiple abnormanl ALNs +/- FNAC, Group D (n=249) : negative ALNs on AUS but SLNB positive . (Results) The median number (range) of ALN metastases were 3(1-22) in GropuA, 2(0-12) in Group B, 7(1-37) in Group C, 1(1-17) in Group D. There were significant differences in number of metastases between Group A/B/C and Group D (p=.02, p=.01, p=.002). Paitents with 3 or less positive ALNs were 24.5% (13/53) in Group C, whereas 61.0% (25/41) in Group A and 68.1% (32/47) in Group B (p=.04, p=.02). We next evaluated the influence of patient- and tumour-related variables on the number of positive ALNs in Group A/B. Factors such as age, tumour size (<20mm vs >20mm), ER status(positive vs negative), HER2 status (positive vs negative), nuclear grade (1/2 vs 3), menstruation status (pre vs post menopausal) were examined. However there were no significant differences in all factors between the patients with 4 or more ALN metastases and patients with 3 or less ALN metastases. As a result of multivariable analysis, relative risk (95%CI, p-value) of age was 0.92 (0.546-1.347, 0.84), tumour size : 0.82 (0.511-1.418, 0.76), ER status : 1.06 (0.873-1.821, 0.76), HER2 status : 1.17 (0.853-2.390, 0.28), nuclear grade : 0.43 (0.420-1.22, 0.34), menstruation status : 0.85 (0.538-1.693, 0.89). (Conclusion) In our contemporary series, patients diagnosed as ALN metastases preoperatively have significantly more involved nodes compared to SLNB positive patients regardless of the diagnostic method, suggesting that such patients should proceed to ALND. Preoperative axillary imaging are useful to identify node-positive breast cancer patients requiring ALND . Citation Format: Naoto Kondo, Takashi Fujita, Masataka Sawaki, Masaya Hattori, Akiyo Yoshimura, Mari Ichikawa, Junko Ishiguro, Yayoi Adachi, Haruru Kotani, Tomoka Hisada, Hiroji Iwata. Preoperative axillary imaging with ultrasonography: Among the breast cancer patients with lymph node metastases, can we identify the patients who may omit axillary dissection? [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-18.