Top Line: Can sentinel lymph node biopsy be omitted in breast cancer patients with a negative axillary ultrasound?
The Study: For early breast cancer, SLNB helps establish the presence or absence of lymph node metastases while negating the adverse effects of axillary dissection. While there is no direct therapeutic benefit to SLNB, there are important therapeutic implications based on its findings. The SOUND trial sought to determine if axillary staging with ultrasound resulted in non-inferior distant disease-free survival for patients with early stage breast cancer. It included 1405 patients of any age with invasive, unifocal breast cancer measuring up to 2 cm. Most (87.8%) had hormone receptor positive, HER2 negative disease, were post-menopausal (78%), and had T1 tumors (95%). They underwent axillary ultrasound prior to randomization, which had to be negative with FNA confirmation of any suspicious nodes. Patients with multiple suspicious nodes were excluded. They were then randomized to standard SLNB or no axillary surgery, and the majority had breast conservation surgery (>99%). In the SLNB group, 13.7% had positive axillary nodes (1 LN in 11.7%, 2+ LN in 2%). Most received adjuvant RT (98%) and adjuvant endocrine therapy (98%) while ~20% received chemo. At 5 years, omitting SLNB did not increase locoregional relapse (1.6% v 1.7%) nor distant metastasis (2% v 1.8%). Distant-DFS was also deemed non-inferior (98% v 97.7%). Key takeaways are that this is a fairly early time point for comparing distant failure and survival outcomes for early stage breast cancer, and that the vast majority of patients had hormone receptor positive disease whose systemic management can be largely driven by genomic recurrence scores. So, caution should be used in applying this to hormone receptor negative disease. Finally, essentially all patients received adjuvant radiation, so we don’t know if it is safe to omit both SLNB and RT for low risk disease.
TBL: Five-year outcomes from the SOUND trial show that locoregional relapse and distant DFS is similar with or without SLNB in patients with favorable biology breast cancer who have negative ultrasound axillary lymph node staging. | Gentilini, JAMA Oncol 2023
The Study: For early breast cancer, SLNB helps establish the presence or absence of lymph node metastases while negating the adverse effects of axillary dissection. While there is no direct therapeutic benefit to SLNB, there are important therapeutic implications based on its findings. The SOUND trial sought to determine if axillary staging with ultrasound resulted in non-inferior distant disease-free survival for patients with early stage breast cancer. It included 1405 patients of any age with invasive, unifocal breast cancer measuring up to 2 cm. Most (87.8%) had hormone receptor positive, HER2 negative disease, were post-menopausal (78%), and had T1 tumors (95%). They underwent axillary ultrasound prior to randomization, which had to be negative with FNA confirmation of any suspicious nodes. Patients with multiple suspicious nodes were excluded. They were then randomized to standard SLNB or no axillary surgery, and the majority had breast conservation surgery (>99%). In the SLNB group, 13.7% had positive axillary nodes (1 LN in 11.7%, 2+ LN in 2%). Most received adjuvant RT (98%) and adjuvant endocrine therapy (98%) while ~20% received chemo. At 5 years, omitting SLNB did not increase locoregional relapse (1.6% v 1.7%) nor distant metastasis (2% v 1.8%). Distant-DFS was also deemed non-inferior (98% v 97.7%). Key takeaways are that this is a fairly early time point for comparing distant failure and survival outcomes for early stage breast cancer, and that the vast majority of patients had hormone receptor positive disease whose systemic management can be largely driven by genomic recurrence scores. So, caution should be used in applying this to hormone receptor negative disease. Finally, essentially all patients received adjuvant radiation, so we don’t know if it is safe to omit both SLNB and RT for low risk disease.
TBL: Five-year outcomes from the SOUND trial show that locoregional relapse and distant DFS is similar with or without SLNB in patients with favorable biology breast cancer who have negative ultrasound axillary lymph node staging. | Gentilini, JAMA Oncol 2023