The AVOID study

Audit to quantify the VOlume of disease on axillary ultrasound in the axIlla, by assessing the cortical thickness and number of abnormal noDes, to support surgical management of the axilla

Overview:  The aim of this audit is to standardise the cortical thickness at a national level to help determine the threshold when needle biopsy of the lymph node is required. We are asking units what their current cortical thickness threshold for axillary biopsy is and we are collecting data on all axillary needle interventions performed in the context of a biopsy proven cancer. The data collected will include benign axillary biopsies as well as malignant biopsies. Collecting the data at this level will help us determine a national cortical thickness threshold and help standardise practice across the UK. It is important when we determine the threshold that we recognise there will be false negatives at SLNB but this should not translate to a completion axillary clearance for low volume disease. It is important to standardise practice to support future audits and research centred around axillary management.


  1. Describe current clinical practice with regards to the ultrasound lymph node cortical thickness threshold required to prompt biopsy at different institutions across the UK.
  2. Describe the association between cortical thickness threshold used and the volume of malignant lymph node disease found with axillary lymph node dissection.

Inclusion/ exclusion criteria

Inclusion criteria

All patients with a new diagnosis of primary invasive breast cancer (B5b) undergoing an axillary lymph node core biopsy. This includes patients having primary surgery, neo-adjuvant chemotherapy and neo-adjuvant endocrine therapy.  

Exclusion criteria

Patients with a new diagnosis of recurrent or metastatic breast cancer.

Planned sample size

Breast Units will be asked to nominate a local lead for the audit and data collection. Each unit will be asked to collect information from 25 consecutive cases where the axilla has been biopsied in patients newly diagnosed with invasive breast cancer. 

Total number of sites planned

No specific number identified – wish to include all screening and symptomatic services



1 year as collecting neoadjuvant cases also. Likely most data collection will happen within 6months

Contact information and website

Dr Nisha Sharma email: