Abstract P5-08-11: Objective Comparison of Post-operative Activity after Sentinel Lymph Node Biopsy versus Axillary Lymph Node Dissection Using Wearable Activity Monitors – The ‘BRACELET’ Study
Authors: Bakri Nur Amalina Che , Kwasnicki Richard , Tenang Luqman , Giannas Emmanuel , Dhillon Kieran , Darzi Ara , Leff Daniel 
Published: March 2023

Abstract
Introduction Axillary de-escalation is driven by both a desire to minimize injury and a growing awareness of the oncological safety of axillary conservation. However, the evidence of the impact of axillary procedures is largely subjective and based on patient questionnaires. Sensing technologies such as Wearable Activity Monitors (WAM) can acquire functional postoperative data, enabling objective analysis of patients’ physical activity (PA) levels. This technology implementation would help surgeons better comprehend the post-operative recovery phase and provide individualized interventions for patients. We aimed to use WAMs in order to investigate differences in physical recovery between axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) – with a hypothesis that the ALND group has slower recovery compared to SLNB. Methods A single centre, prospective non-randomized observational study was conducted from September 2019 to May 2022. Consecutive patients undergoing breast and axillary surgery were identified from theatre lists. Patients with movement disorders or upper limb impairment and those using mobility devices or aids were excluded. Eligible consented patients wore WAMs (AX3, Axivity, UK – triaxial accelerometer) on both wrists at least one day pre- and up to two weeks post-operatively. The Mann-Whitney U test and the Wilcoxon Signed Rank Test were performed to analyze the PA levels between arms and surgeries. Patient demographics and potential confounders such as concomitant breast/reconstruction surgery were recorded. Results A total of 53 patients were recruited. Greater PA level was observed in the control arm compared to the surgically treated side in both SLNB and ALND groups in week 1 (SLNB: 69.6% vs 61.1%, p=0.006; ALND: 75.3% vs 60.4%, p&lt; 0.001) and 2 (SLNB: 77.6% vs 71.1%, p=0.113; ALND: 81.9% vs 70.2%, p&lt; 0.001) respectively. When comparing activities of the surgically treated side only, the ALND patients had significantly lower PA level compared to SLNB group in post-operative day 7-9 (65.4% vs 72.5%, p=0.035). Subgroup analysis was performed to compare surgically treated side of ‘Mastectomy Only and SLNB’ versus ‘Mastectomy Only and ALND’. PA level was significantly lower in the latter than the former in week 2 (78.5% vs 83.5%, p=0.027). There were no significant differences in demographics between the 2 groups. Conclusion ALND consistently results in decreased PA level compared to SLNB. The findings also demonstrate the longitudinal impact of SLNB, which impacts PA levels, even up to 2 weeks after surgery. Monitoring recovery objectively after breast cancer surgery provides patients and surgeons with more information about the likely outcomes of their treatment and may help them choose the best option, particularly where oncological outcomes are equivocal. This information could also be used to improve outcomes by identifying vulnerable patients who would benefit from early exercise intervention, encouraging physical activity, and keeping track of individualised PA that could be added to the feedback rehabilitation care plan.
Citation Format: Nur Amalina Che Bakri, Richard Kwasnicki, Luqman Tenang, Emmanuel Giannas, Kieran Dhillon, Ara Darzi, Daniel Leff. Objective Comparison of Post-operative Activity after Sentinel Lymph Node Biopsy versus Axillary Lymph Node Dissection Using Wearable Activity Monitors – The ‘BRACELET’ Study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-08-11.