Optimise viewing for

Toggle between patient and health professional views. The patient version is simplified to help people easily find suitable trials, while the professional view provides full detail.

No longer recruiting (closed or complete)Last updated: 16 December 2025

POSNOC: This trial is comparing the effect of having adjuvant therapy on its own, or in combination with axillary treatment, in women with early stage breast cancerPOsitive 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

Trial purpose

Medical clipboardCancer treatment

Tumor type

Breast Cancers Breast

Age

People18+

Trial acronym

POSNOC

Clinical summary

Summary

POSNOC is a pragmatic, randomised, multicentre, non-inferiority trial. Aim For women with early stage breast cancer and one or two sentinel node macrometastases, to assess whether adjuvant therapy alone is no worse than adjuvant therapy plus axillary treatment, in terms of axillary recurrence within 5 years. Stratification: Institution, Age (<=50, 50), Breast-conserving surgery (BCS) or mastectomy, Estrogen receptor (ER) status (positive, negative), Number of positive nodes (1, 2), Intra-operative sentinel assessment using OSNA (yes, no). Interventions The study will compare adjuvant therapy alone with adjuvant therapy plus axillary treatment (axillary node clearance (ANC) or axillary radiotherapy (ART)). Sample Size: 1900 participants Follow-up: Participants will be followed up for 5 years. Adjuvant Therapy: All participants will receive adjuvant systemic therapy (chemotherapy and/or endocrine therapy). All participants may receive breast/chest wall radiotherapy. Axillary and supraclavicular fossa radiotherapy is not allowed when randomised to adjuvant therapy alone.

Conditions

This trial is treating people with breast cancer

Eligibility

Inclusion

  • 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 neoadjuvant therapy (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 macrometastasis on molecular assay)
  • Fit for axillary treatment and adjuvant therapy
  • Have given written informed consent

Exclusion

  • bilateral invasive breast cancer
  • more than 2 nodes with macrometastases
  • neoadjuvant therapy for breast cancer except:

    • if sentinel node biopsy performed prior to neoadjuvant chemotherapy in women with early breast cancer
    • short duration of neoadjuvant endocrine therapy is acceptable (up to 3 months)
  • 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:

    • basal or squamous cell carcinoma of the skin
    • in situ carcinoma of the cervix
    • in situ melanoma
    • contra- or ipsilateral in situ breast cancer

Exclusion

  • You have been diagnosed with a prior or secondary type of cancer.
  • You have certain types of non-cancer medical conditions.
Message

Clinical trials have complex eligibility criteria, and other criteria may apply for this trial. Ask your doctor about whether this trial could be right for you.

Participating hospitals

+ Show non-recruiting hospitals

No longer recruiting (closed or complete) hospitals

InformationTell us if you find this trial availability is not accurate.Report inaccuracy

More information

Trial Identifiers

Information on this page is partially produced from ClinicalTrials.gov, UK’s Clinical Study Registry *. View further details about this trial on the registry via the links below:

Trial sponsor

Melbourne Health

Scientific Title

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

Get Support

Peer Connect

You might find it helpful to speak to someone who has 'been there before'. Our Peer Connect program can provide one-on-one phone support from someone who understands what you're going through and has clinical trials experience.

Know more about Peer Connect

Contact cancer support

If you need cancer information and practical support for yourself, a carer, family or friend, contact Cancer Council to speak with an experienced health professional on 13 11 20.

Get support

Multilingual information

Learn more about clinical trials through this collection of resources in languages other than English.

View information