Abstract PS1-55: Clipping of involved axillary lymph nodes before Neo adjuvant chemotherapy may improve in identification rates & staging of axilla in breast cancer

Abstract

Abstract Introduction: Neo adjuvant chemotherapy is increasingly being employed in breast cancer to reduce tumour size & down stage axilla. To reduce false negative rates in axillary lymph nodes after down staging with chemotherapy and to improve axillary conservation ultrasound guided clips were placed in involved axillary lymph nodes prior to commencement of NACT. The study aimed at whether preoperative lymph node clipping had any benefit in identification of lymph node after NACT.Methods: This is a single centre study of 55 patients (Mean age 53 years) with invasive breast cancer with biopsy proven involved lymph nodes (T1-3 N1) who underwent ultrasound guided axillary marker clip insertion before start of NACT. If Post chemotherapy imaging showed normal lymph nodes patients underwent SLNB with additional Lymph Nodes sampled to achieve a total of 4 lymph nodes. All sampled nodes were x rayed at the time of surgery to identify marker clip.Results: We had no procedure related complications with insertion of marker clip in any patients. The median number of nodes was 4.0. Average lymph nodes retrieved was 4.9. SLNB was identified in 47/55 patients (85.5%). Median number of sentinel nodes was 3.0 (Range 1-7) Marker was identified in 41/55 patients (74.5%) 30 (54.5%) patients had marker in sentinel node and 11 (20%) patients had marker in non-sentinel node. Histologically clip was reported in 21 (51.2%) patients. Overall pathological complete response (pCr) in axilla was seen 31/55 (56.45%). Tumours with Her2 over expression showed pCr in axilla 83% n=19/23 while triple negative tumours showed pCr in axilla 64% n=9/14. Er+ Her2- tumours showed low pCr rate 16.7% n=3/18. Completion axillary clearance was performed in 14/24 patients and 10/24 received radiotherapy to axilla.Conclusions: Clips in axillary lymph nodes are safe & relatively easy to deploy without any increased morbidity. Our clip identification rate (74.5%) co relates with other well-known publications (Caudel et al 80%, Z1071-76%). Our study findings validate that clip placement improves the identification of involved lymph nodes and hence improve the accuracy of limited axillary dissection in staging axilla. Citation Format: Mohammad Bilal Elahi, Raouef Ahmed Bichoo, Kartikae Grover, Eiman Khalifa, Naila Bint Ihsan, Peter J Kneeshaw, Brendan Paul Wooler, Dorin Dumitru, Ronjabati Roychaudhury, Ayesha Rahman, Tapan Kumar Mahapatra. Clipping of involved axillary lymph nodes before Neo adjuvant chemotherapy may improve in identification rates & staging of axilla in breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-55.