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.