Abstract ES8-4: Axillary management in upfront surgery - staging, local control or both?

Abstract

Abstract Axillary management in women undergoing upfront surgery for operable breast cancer has changed dramatically over the last several decades. Axillary lymph node dissection (ALND), a procedure that was historically used in both clinically node negative and node positive patients to stage the axilla and optimize locoregional control, is associated with the potential for significant long-term morbidity in the form of upper extremity lymphedema, paresthesia, and shoulder dysfunction. Efforts to minimize the morbidity associated with ALND, as well as the recognition that only a minority of patients with clinically node negative disease are found to have nodal metastases at the time of axillary surgery, prompted the development and validation of sentinel lymph node biopsy (SLNB). In women who are clinically node negative, SLNB has been shown to accurately stage the axilla without compromising oncologic outcomes, identifying nodal disease in up to 30% of cases. The application of clinical trial data from Z0011 and AMAROS in T1-T2 breast cancer with 1-2 positive lymph nodes undergoing breast conservation allow for omission of completion ALND with no impact on locoregional control or survival. The ongoing POSNOC trial (NCT02401685) will further determine whether women with T1-T2 disease undergoing breast conservation or mastectomy require directed axillary treatment in the form of ALND or axillary radiation to minimize the risk of axillary failure. An altogether omission of axillary staging in clinically node negative breast cancer remains an area of evolving interest, with CALGB 9343 trial data supporting this approach in older women with stage I estrogen-receptor positive (ER+) HER2- breast cancer. Trials examining the omission of SLNB in other select patient populations with negative axillary imaging are the subject of ongoing investigation. At present, prognostic information derived from SLNB for clinically node negative women undergoing upfront surgery for early-stage triple negative and HER2+ breast cancer, premenopausal ER+HER2- breast cancer, and BRCA1/2-associated breast cancer remain important for adjuvant systemic therapy decision-making. Citation Format: S Wong. Axillary management in upfront surgery - staging, local control or both? [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr ES8-4.