It has been suggested that selective sentinel node (SN) biopsy alone can be used to manage early breast cancer, but definite evidence to support this notion is lacking. The aim of this study was to investigate whether refraining from completion axillary lymph node dissection (ALND) suffices to produce the same prognostic information and disease control as proceeding with completion ALND in early breast cancer patients showing micrometastasis at SN biopsy.

This prospective, randomized clinical trial included patients with newly diagnosed early-stage breast cancer (T<3.5 cm, clinical N0, M0) who underwent surgical excision as primary treatment. All had micrometastatic SN. Patients were randomly assigned to one of the two study arms: complete ALND (control arm) or clinical follow-up (experimental arm). Median follow-up was 5 years, recurrence was assessed, and the primary end point was disease-free survival.

From a total sample of 247 patients, 14 withdrew, leaving 112 in the control arm and 121 in the experimental arm. In 15 control subjects (13%), completion ALND was positive, with a low tumor burden. Four patients experienced disease recurrence: 1 (1%) of 108 control subjects and 3 (2.5%) of 119 experimental patients. There were no differences in disease-free survival (p=0.325) between arms and no cancer-related deaths.

Our results strongly suggest that in early breast cancer patients with SN micrometastasis, selective SN lymphadenectomy suffices to control locoregional and distant disease, with no significant effects on survival.