Breast cancer patients with a negative axillary ultrasound may have clinically significant nodal metastasis.

INTRODUCTION: The non-invasive nature of the preoperative axillary ultrasound (AUS) fits the current trend of increasingly conservative axillary management. Recent publications suggest that early disease patients with clinically and radiologically negative axillae do not require sentinel lymph node biopsy (SLNB). This study aims to determine the true extent of axillary node disease in negative preoperative AUS patients. METHODS: A 10-year breast cancer registry was reviewed to identify women with pathologically confirmed T1-2 invasive breast cancer and a negative preoperative AUS. Patients who received neoadjuvant chemotherapy were excluded. Combined positive lymph node count of SLNB ± ALND was used to determine total nodal burden (TNB). Axillae were classified into low nodal burden (LNB) defined as 1-2 positive nodes and high nodal burden (HNB) defined as ≥ 3 positive nodes. RESULTS: 762 patients with negative AUS were included. There were 46.9% and 53.0% T1 and T2 tumours, respectively. 76.9% were node negative (0 LN +), 18.9% had LNB (1-2 LN +) and 4.2% had HNB (≥ 3LN +). Specifically, HNB disease was seen in 2% of T1 tumours and 6.2 % of T2 tumours with a negative AUS. In multivariate analysis, T2 strongly associated with ≥ 3 positive ALNs (OR 2.66 CI 1.09-6.51 p = 0.03) as did lymphovascular invasion (OR 3.56 CI 1.52-8.30 p = < 0.01). CONCLUSION: This study shows that AUS in its current form cannot exclude HNB axillary metastasis to the extent of eliminating the need for surgical staging of the axilla. This may impact axillary local-regional recurrence and disease-free survival. We caution that a negative AUS has a rate of 4.2% of HNB. Therefore, in cases of negative AUS with a T2 tumour, we advocate continued use of SLNB.

Value of Long-term Follow-up in Surgically Excised Lesions of Uncertain Malignant Potential in the Breast - Is 5 Years Necessary?

INTRODUCTION: B3 lesions are a heterogeneous group of breast lesions of uncertain malignant potential which usually require excision. The aim was to assess the efficacy of 5 years routine radiological or clinical follow-up of patients who had "high-risk" B3 lesions surgically excised, by analyzing recurrence and subsequent development of invasive/in-situ cancer. PATIENTS AND METHODS: A 10-year retrospective review from 2010 to 2019 was performed of B3 lesions diagnosed on core needle biopsy, including patients who proceeded to surgical excision with a high-risk lesion on final histology. The database recorded 6 specific B3 lesion categories: 1. Atypical ductal hyperplasia (ADH), 2. Radial scars/complex sclerosing lesions (CSLs) with epithelial atypia 3. Classical Lobular neoplasia (ALH/LCIS), 4. Papillary lesions with epithelial atypia, 5. Mixed, 6. Flat epithelial atypia (FEA), including radiological and clinical follow-up data. RESULTS: Six hundred sixteen patients had a B3 lesion after core biopsy. 110 patients had "high risk" lesions. This included 17 (15.5%) Atypical Ductal Hyperplasia (ADH), 22 (20%) radial scars/CSLs with epithelial atypia, 47 (42.7%) classical lobular neoplasia (LCIS/ALH), 7 (6.4%) papillary lesions with epithelial atypia, 13 (11.8%) mixed lesions & 4 (3.6%) Flat Epithelial Atypia (FEA) lesions. 4 of 110 (3.6%) developed invasive/in-situ disease and 4 of 110 (3.6%) developed recurrence during follow-up. 33 of 616 (5.4%) upgraded to invasive/preinvasive disease after surgical excision. CONCLUSION: Five years of routine radiological surveillance may not be necessary in patients who undergo surgical excision of "high-risk" B3 lesions. Clinical surveillance appears to be of little benefit, especially in patients with radial scars, papillary lesions, and FEA. Subsequent development of invasive/in-situ disease in patients who undergo surgical excision of atypical B3 lesions remains low.