POSNOC - POsitive Sentinel Node: Observation versus Clearance or radiotherapy: A randomised controlled trial of axillary treatment in patients with early stage breast cancer who have metastases in one or two sentinel nodes.

The hypothesis of the POSNOC trial is that low axillary tumour burden patients (clinically and ultrasound negative) with macrometastases in 1 or 2 SNs, receiving systemic therapy, would have non-inferior outcomes whether they are randomised to adjuvant therapy alone or adjuvant therapy plus axillary treatment (ANC or ART).


Primary outcome measure

The primary outcome is axillary recurrence at 5 years.

Secondary outcome measures

Secondary outcomes assessed at 3, 6, 12, 24 and 36 months are:

  • Arm morbidity
  • Quality of life
  • Anxiety
  • Economic outcomes

Secondary outcomes assessed at 6, 12, 24, 36, 48 and 60 months are:

  • Local (breast or chest wall) recurrence
  • Regional (nodal) recurrence
  • Distant metastasis
  • Time to axillary recurrence
  • Axillary recurrence free survival
  • Disease free survival
  • Overall survival
  • Contralateral breast cancer
  • Non-breast malignancy


Inclusion/ exclusion criteria:

Inclusion criteria

  • Women will be eligible for inclusion only if ALL of the following criteria apply:
  • 18 years or older
  • Unifocal or multi-focal invasive tumour with lesion ≤5 cm in its largest dimension, measured pathologically or largest invasive tumour diameter on radiology should be used for women who are randomised intra-operatively or undergo sentinel node biopsy before neoadjuvanttherapy (tumour size should be based only on the single largest tumour; do not add the sizes together from the multiple foci)
  • At sentinel node biopsy have 1 or 2 nodes with macrometastases (tumour deposit >2.0mm in largest dimension or defined as macrometastases on molecular assay)
  • Fit for axillary treatment and adjuvant therapy
  • Have given written informed consent

Exclusion criteria

  • bilateral breast cancer
  • more than 2 nodes with macrometastases
  • neoadjuvant therapy for breast cancer
  • previous axillary surgery on the same body side as the scheduled sentinel node biopsy
  • not receiving adjuvant systemic therapy
  • previous cancer less than 5 years previously or concomitant malignancy except
    • adequately treated basal or squamous cell carcinoma of the skin or
    • adequately treated in situ carcinoma of the cervix or
    • adequately treated in situ melanoma 
    • contra- or ipsilateral in situ breast cancer


Planned sample size:


End of February 2020: n=1649 recruited

Total number of sites:

111 hospitals in the UK and
20 centres in Australia and New Zealand


Completing recruitment: 31st August 2021

Contact Information

Mr Amit Goyal (CI): amit.goyal@nhs.net

Shabina Sadiq (Trial Manager): posnoc@nottingham.ac.uk

POSNOC website

Cancer Research UK Website