From Clinical Trial Awareness to Practice: Factors Associated with Intent to Omit Axillary Surgery Based on the SOUND Clinical Trial

Abstract Background The SOUND trial, published in 2023, demonstrated the oncologic safety of sentinel lymph node biopsy (SLNB) for select patients with early-stage breast cancer. We evaluated whether earlier awareness of the results of the SOUND trial was associated with increased intent to implement SLNB omission. Methods This multicenter, cross-sectional study surveyed North American physicians on current SLNB use, awareness of the SOUND trial results, and intent to implement trial findings. Intent was measured using the Innovation-Specific Implementation Intentions scale and scenario-based questions (ages 50 vs 60; whole- vs partial-breast irradiation), on a 5-point scale. The primary outcome was high intent to omit SLNB (“moderate” to “very great” extent). Multiple logistic regression identified factors associated with intent. Results The response rate was 21% (208/1004): 148 (71.5%) surgeons, 32 (13.04%) medical and 27 (15.46%) radiation oncologists. Overall, 47.8% had already omitted SLNB in select patients aged < 70 years, and 63.6% reported high intent to use SOUND results. Among those who had not yet omitted SLNB ( n = 108), 59.3% had high intent. Length of awareness of the SOUND trial (odds ratio 1.13) and practicing in Northeast USA vs Western USA (odds ratio 3.45, p = 0.032) were associated with increased intent to omit SLNB. In scenario-based questions, most endorsed omission for a 60-year-old patient receiving whole-breast irradiation ( n = 105 50.5%); willingness decreased for a 50 year old or when partial-breast irradiation was planned. Across scenarios, intent was not associated with SOUND awareness duration, clinician characteristics, or referral workflows. Conclusions Earlier awareness of the SOUND trial and regional differences were associated with greater intent to omit SLNB.