Abstract OT2-1-02: Clinical node negative breast cancer patients undergoing breast conserving therapy: follow-up versus sentinel lymph node biopsy

Abstract

Abstract Background: The ACOSOG-Z0011 study demonstrated no additional value of complementary axillary lymph node dissection in case of limited axillary sentinel lymph node (SLN) metastases in breast cancer patients undergoing breast conserving therapy1. Since axillary ultrasound can exclude advanced axillary metastatic disease pre-operative2, there is ample opportunity to evaluate whether SLN biopsies are still indicated in a selected group of breast cancer patients. Trial design: A prospective non-inferiority randomized multicenter trial was designed. Breast cancer patients with cT1-2N0 disease, with no evidence for axillary metastases on ultrasound, treated with breast conserving therapy (lumpectomy + whole breast radiotherapy), will be randomized between follow-up and SLN biopsy. If adjuvant systemic therapy is not indicated by tumor or patient characteristics, gene expression profiling may be used for evaluation. To assess Quality of Life, 3 validated questionnaires will be used: QLQ-C30, QLQ-BR 23 and Lymph-ICF3-5. Eligibility criteria: – Women with histological confirmed cT1-2 invasive unilateral breast carcinoma– Clinical node negative: no palpable nodes at physical examination and an axillary ultrasound without signs of lymph node metastases (cyto-/histology if indicated)– Neoadjuvant systemic therapy is allowed. Specific aims: Primary endpoint is the axillary recurrence rate. The number of delayed axillary dissections will be registered. Secondary endpoints are distant-disease free survival, overall survival, local recurrence, morbidity and Quality of Life. Statistical methods: Based on a 5-year axillary recurrence free survival rate: failure rate of 0.99 for controls and a true failure rate of 0.96 (as considered acceptable) for study subjects. Overall, 2086 patients will be included to be able to reject the null hypothesis that the failure rate for experimental and control subjects is inferior by at least 5% (D = −5%) with probability of 0.8 and alpha of 5%. Present accrual and target accrual: This study is expected to start in late 2012 after approval by the Ethical Medical Committee.