Abstract OT2-1-03: The Z11 design for breast cancer patients undergoing a mastectomy

Abstract

Abstract Background: The diagnostic work-up and treatment of axillary lymph nodes in breast cancer patients is an ongoing topic of research. The ACOSOG-Z0011 study demonstrated no additional value of complementary axillary lymph node dissection (cALND) in case of limited axillary sentinel lymph node (SLN) metastases in breast cancer patients undergoing breast conserving therapy1. It is questionable whether these results can be applied to patients undergoing a mastectomy2. Trial design: A prospective non-inferiority randomized multicenter trial was designed. Breast cancer patients with cT1-2N0 disease treated with mastectomy and limited axillary SLN metastases will be randomized for follow-up versus complementary axillary treatment. To assess the Quality of Life and morbidity benefits of this experimental treatment, 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 in physical examination and the axillary ultrasound without signs of lymph node metastases (cyto-/histology if indicated)– Sentinel lymph node biopsy must contain at least one and a maximum of 3 (micro)metastases– 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 5-year axillary recurrence free survival rate, a failure rate of 0.98 among controls and a true failure rate of 0.96 for study subjects are considered acceptable. Overall, 1114 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.