Trends in Surgical Axillary Staging and Clinical Outcomes Among Breast Cancer Patients With Neoadjuvant Therapy: A Population-Based Cohort Study.

OBJECTIVES

Surgical management of the axilla with neoadjuvant treatment has been a significant research focus over the past decade, resulting in numerous publications. The trends in surgical choices based on lymph node status and survival outcomes in large populations were previously unclear.

METHODS

Breast cancer patients who underwent neoadjuvant therapy were identified from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2021 and categorized into 2 cohorts: LN- (no lymph node metastasis) and LNm (1-2 sentinel node metastases). We analyzed the trends in surgical axillary staging and compared the 10-year overall survival between sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND).

RESULTS

Among 26,320 patients, 18,548 were in the LN- cohort (16,607 with SLNB and 1,941 with ALND) and 7,772 were in the LNm cohort (3,601 with SLNB and 4,171 with ALND). The proportion of patients undergoing SLNB increased from 76.4% in 2010 to 93.8% in 2021 in the LN- cohort and doubled from 25.2% in 2010 to 55.0% in 2021 in the LNm cohort. ALND was identified as a favorable factor over SLNB in the LNm cohort (hazard ratio [HR] 0.84; 95% CI, 0.73-0.96; P = .014).

CONCLUSION

Omission of ALND for patients with 1 to 2 node metastases after neoadjuvant therapy has doubled since 2010. SLNB is an efficient and safe approach of surgical axillary staging for the LN- cohort but not for patients with residual axillary cancer, even with low-volume disease.