Applying the SOUND trial for omitting axillary surgery to patients with early breast cancer in Bahrain

Abstract

Abstract Purpose The SOUND trial reported that omission of axillary surgery was not inferior to sentinel lymph node biopsy (SLNB) in those with cT1 breast cancer and negative preoperative axillary ultrasound. The aim of our study was to evaluate the clinical characteristics of early breast cancer patients undergoing breast conserving surgery (BCS) at our institution in order to investigate the exportability of SOUND criteria to our patient population. Methods We retrospectively reviewed patients with cT1N0 breast cancer undergoing BCS and adjuvant radiotherapy at our institution according to the SOUND trial criteria. Comparison was made between the eligible group of our cohort and the no axillary surgery arm of the SOUND trial using the chi-squared test. Results The proportion of younger patients was higher in our eligible cohort (37.7% vs 19.8%, P = 0.002). Postmenopausal patients were observed with a higher percentage in the SOUND trial (77.7% vs 56.6%, P = 0.004). On final pathology, tumours were more likely to be upgraded to T2 in our group (26.4% vs 5%, P = 0.001). Patients in our cohort were more likely to receive adjuvant chemotherapy (37.7% vs 17.5%, P = 0.002). Conclusion The clinicopathological differences between our cohort and the no axillary surgery arm in the SOUND trial could be attributed to aggressive tumours in Bahrain compared to Western countries. Although this trial is unlikely to change guidelines immediately, it should generate multidisciplinary discussion in the de-escalation of axillary surgery. Our study may influence other surgeons to incorporate the SOUND trial into clinical practice.