31 May 2017


The POSNOC trial is a clinical research trial available in NZ looking at the armpit treatment provided to women diagnosed with early stage breast cancer and one or two sentinel nodes involved with cancer spread. The trial will help determine if axillary treatment is no longer needed meaning that some wāhine/women will be able to avoid unnecessary treatment and long term side effects of treatments.

POSNOC is of considerable importance in terms of improving outcomes for women with breast cancer and also in understanding breast biology.

Scientific Title

Protocol RD-5103-001-13: POsitive Sentinel NOde: adjuvant therapy alone versus adjuvant therapy plus Clearance or axillary radiotherapy. A randomised controlled trial of axillary treatment in women with early stage breast cancer who have metastases in one or two sentinel nodes or “POSNOC trial”.


The usual treatment following breast cancer surgery is to give chemotherapy or endocrine therapy (hormone therapy), or both. Radiotherapy may also be given to the breast or chest wall. These treatments are called adjuvant therapy.

At the moment, it is also usual for women with cancer spread in 1 or 2  lymph sentinel nodes to have further treatment to their armpit (axilla). This treatment is either an operation to remove extra lymph nodes from the armpit (axillary node clearance), or radiotherapy to the armpit (axillary radiotherapy).  Researchers want to find out whether this further treatment to the armpit is really needed.

Researchers now know that other breast cancer treatments are very good at preventing cancer from coming back. Some research results suggest that the extra armpit treatment after sentinel node biopsy may not change the risk of cancer coming back so the axillary treatment may no longer be needed. However, many experts believe that further evidence is needed to prove whether this is the case.



This UK based trial will involve 1900 women across the UK, Australia, and NZ. Waikato, Rotorua, and Palmerston North Hospitals will be centres for this research.

Ask your Breast Surgeon or Oncologist if this trial is suitable for you.