Locoregional Control With Radiotherapy of Breast Cancer Patients With MACrometastases Treated With MAstectomy (MACMA)

Overview

Sentinel lymph node biopsy (SLNB) is the standard procedure to stage the axilla in clinically node-negative invasive breast cancer (IBC) patients undergoing upfront surgery. The ACOSOG-Z0011 and the AMAROS trial demonstrated that SLNB with or without radiotherapy provided equivalent local control and survival to axillary lymph node dissection (ALND) in early-stage breast cancer patients with 1 or 2 positive SLNs. However, the ACOSOG-Z0011 trial did not included patients treated with mastectomy, and the AMAROS trial only included 17% of mastectomy patients. The investigators conduct an observational cohort study of early stage breast cancer patients receiving upfront mastectomy with 1 or 2 macrometastases after SLNB. The study aim to demonstrate a 5-year disease-free survival of not less than 80% when ALND is omitted and replaced by axillary radiotherapy, and determine the axillary recurrence rate.

This is a multi-center, prospective study with an estimated sample size of 60 early-stage IBC patients. Clinically node-negative T1-2 IBC patients undergoing mastectomy with up to 2 macrometases after SLNB will be informed about this study. Patients will be checked with annual mammography and clinical examination. The axilla will be checked with ultrasound at 3 and 5 years of the surgery. After surgery, patients will receive axillary radiotherapy, but no ALND, and adjuvant systemic treatment based on international guidelines.

Conditions

Interventions