Which Patients with Sentinel Node–Positive Breast Cancer Can Avoid Axillary Dissection?

Abstract

Sentinel lymph node (SLN) biopsy is standard care for patients with cN0 breast cancer. An extensive literature, including seven randomized trials, has established that patients with negative SLN do not require axillary dissection (ALND), that axillary local recurrence after a negative SLN biopsy is rare, that disease-free and overall survival are unaffected by the addition of ALND to SLN biopsy, and that the morbidity of SLN biopsy is substantially less than that of ALND. It is now clear that many patients with positive SLN do not require ALND. In ACOSOG Z0011, 6-year locoregional control and survival were equivalent with versus without the performance of ALND in cT1-2N0 patients with ≤2 positive SLN treated by breast conservation with whole breast radiation therapy. A small but growing body of data now suggests that ALND may not be required for selected patients outside the Z0011 eligibility criteria, specifically those treated by mastectomy (without post-mastectomy radiation therapy), by partial breast irradiation, and by neoadjuvant chemotherapy. Looking ahead, the principal goals of axillary staging, prognostication, and local control will be accomplished by SLN biopsy for a substantial majority of patients, and the role of ALND will continue to diminish.