Abstract PS1-62: Two decades of experience with sentinel node staging of axilla - is false negative no longer a worry?
Authors: Arif Tahera , Absar Mohammed Shamim 
Published: February 2021

Abstract
Aim: To review current literature and standard practices in various techniques of sentinel node biopsy for staging the axilla for treating early breast cancer. The purpose is to provide evidence based recommendation as guidance platform for optimal true sentinel node retrieval irrespective of surgeon expertise. Background: Axillary conservation is the way forward after game changing trials like ACOSOG Z0011, surrogate trials like IBCSG,AMAROS, ALMANAC, ongoing POSNOC, and newbie ATNEC have progressively or plan to decrease the need to unnecessarily fiddle with the axilla thereby increasing the chances of arm related and other morbidities. Axillary sentinel node biopsy entails retrieval of first draining lymph node in the breast-axilla pathway to plan treatment in breast cancer by appropriate staging of axilla. Current standard is the utilisation of double agent technique with radioactive isotope and blue dye injection to decrease false negative rates for true sentinel node retrieval. Novel techniques like magnetic and infrared tracing are still being investigated for validation. Method: PMC, Medline, EMBASE, PubMed and Cochrane library searched for clinical trials, randomised trials, systematic reviews and meta-analysis on techniques of axillary sentinel node biopsy in early breast cancer. This covered the last 25 years literature on the topic. Results: The search yielded 197 publications which were subjected to a meticulous review and narrowed to a select pertinent body of evidence to extrapolate suggested guidance rationally, the bibliography of which is provided at the end. Conclusion: Single agent preferably radioisotope for lymphatic mapping is recommended in palpable and good biology tumours. Use of single agent blue dye can be standardised in axillary tail tumours. It is also recommended as being effective when isotope mapping is logistically not feasible or during pandemics like COVID 19 where looming infrastructure challenges are prevalent. Dual agent technique should be considered in previously treated breast and axilla, neoadjuvant chemotherapy cohort, bad tumour biology, high BMI and macromastia groups for true nodal retrieval. Optimal number of nodes taken out should not be more than three (n=3). Lower axillary sampling of not more than 3 nodes is recommended for troubleshooting with any localising agent technique. Triple site injection at peri-tumoural, subcutaneous and sub areolar regions and larger volume of blue dye agent injection of up to 8mls increases the localisation success in the dual technique group for lymphatic mapping. Magnetic tracing can be used as an adjunct to either single agent radioactive isotope or blue dye (RI/BD) technique when there is failure to localise the sentinel node.
Citation Format: Tahera Arif, Mohammed Shamim Absar. Two decades of experience with sentinel node staging of axilla - is false negative no longer a worry? [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 PS1-62.