POSNOC - A Trial Looking at Axillary Treatment in Early Breast Cancer

Condition(s) studied

Investigational drug(s) / intervention(s)

Adjuvant therapy: Adjuvant therapy will include chemotherapy and/or endocrine therapy for all women, and radiotherapy to breast or chest wall if indicated. Human epidermal growth factor receptor 2 (HER2) targeted treatment may also be administered when indicated.

Axillary treatment: Axillary treatment can be axillary node clearance or axillary radiotherapy as per local guidelines.

Study 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.

Eligibility

Primary outcome measure(s)

• Axillary recurrence — 5 years
  Axillary recurrence is defined as pathologically (cytology or biopsy) confirmed recurrence in lymph nodes draining the primary tumour site.

Trial sites (50)

+ 10 more sites — see the full list on the official registry below.

Other trials for the same condition