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.
Patient Population
Women with unifocal or multifocal invasive breast cancer, largest primary lesion ≤5cm, clinically and ultrasound node negative, who undergo sentinel node biopsy (SNB) and have 1 or 2 sentinel node macrometastases (>2mm), with no extranodal extension.
Stratification
- Institution
- Age (<50, ≥50)
- Breast-conserving surgery (BCS) or mastectom
- Estrogen receptor (ER) status (positive, negative
- Number of positive nodes (1, 2)
Interventions
The study will compare adjuvant therapy alone with adjuvant therapy plus axillary treatment (axillary node clearance (ANC) or axillary radiotherapy (ART).
Primary Outcome
Axillary recurrence at 5 years
Secondary Outcomes
- Arm morbidity
- Quality of life
- Anxiety
- 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
- Economic evaluation
Sample Size
1900 participants
Duration of Recruitment and Follow-up
Recruitment is from July 2014 and ended on 13-July-2021. Participants will be followed up for 5 years.
Protocol Version 7.0 includes: Addition of collection of participant health status from routine medical records till end of data collection period (2026)
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.
POSNOC Protocol version 8.0 13-Feb-2024