Changes in Surgical Management of the Axilla Over 11 Years – Report on More Than 1500 Breast Cancer Patients Treated with Neoadjuvant Chemotherapy on the Prospective I-SPY2 Trial

• Published in: Annals of surgical oncology 2023-10, Vol.30 (11), p.6401-6410
• Main Authors: Boughey, Judy C., Yu, Hongmei, Dugan, Catherine Lu, Piltin, Mara A., Postlewait, Lauren, Son, Jennifer D., Edmiston, Kirsten K., Godellas, Constantine V., Lee, Marie C., Carr, Michael J., Tonneson, Jennifer E., Crown, Angelena, Lancaster, Rachel B., Woriax, Hannah E., Ewing, Cheryl A., Chau, Harrison S., Patterson, Anne K., Wong, Jasmine M., Alvarado, Michael D., Yang, Rachel L., Chan, Theresa W., Sheade, Jori B., Ahrendt, Gretchen M., Larson, Kelsey E., Switalla, Kayla, Tuttle, Todd M., Tchou, Julia C., Rao, Roshni, Tamirisa, Nina, Singh, Puneet, Gould, Rebekah E., Terando, Alicia, Sauder, Candice, Hewitt, Kelly, Chiba, Akiko, Esserman, Laura J., Mukhtar, Rita A.
• Format: Article
• Language: English
• Subjects: Axilla - pathology; Breast cancer; Breast Neoplasms - drug therapy; Breast Neoplasms - pathology; Breast Neoplasms - surgery; Breast Oncology; Chemotherapy; Clinical trials; Diagnosis; ErbB-2 protein; Female; Humans; Lymph Node Excision; Lymph nodes; Lymphatic Metastasis - pathology; Lymphatic system; Medicine; Medicine & Public Health; Neoadjuvant Therapy - methods; Oncology; Patients; Prospective Studies; Sentinel Lymph Node - pathology; Sentinel Lymph Node - surgery; Sentinel Lymph Node Biopsy - methods; Surgery; Surgical Oncology
• ISSN: 1068-9265; 1534-4681; 1534-4681
• DOI: 10.1245/s10434-023-13759-y

Background Axillary surgery after neoadjuvant chemotherapy (NAC) is becoming less extensive. We evaluated the evolution of axillary surgery after NAC on the multi-institutional I-SPY2 prospective trial. Methods We examined annual rates of sentinel lymph node (SLN) surgery with resection of clipped node, if present), axillary lymph node dissection (ALND), and SLN and ALND in patients enrolled in I-SPY2 from January 1, 2011 to December 31, 2021 by clinical N status at diagnosis and pathologic N status at surgery. Cochran-Armitage trend tests were calculated to evaluate patterns over time. Results Of 1578 patients, 973 patients (61.7%) had SLN-only, 136 (8.6%) had SLN and ALND, and 469 (29.7%) had ALND-only. In the cN0 group, ALND-only decreased from 20% in 2011 to 6.25% in 2021 ( p = 0.0078) and SLN-only increased from 70.0% to 87.5% ( p = 0.0020). This was even more striking in patients with clinically node-positive (cN+) disease at diagnosis, where ALND-only decreased from 70.7% to 29.4% ( p < 0.0001) and SLN-only significantly increased from 14.6% to 56.5% ( p < 0.0001). This change was significant across subtypes (HR−/HER2−, HR+/HER2−, and HER2+). Among pathologically node-positive (pN+) patients after NAC ( n = 525) ALND-only decreased from 69.0% to 39.2% ( p < 0.0001) and SLN-only increased from 6.9% to 39.2% ( p < 0.0001). Conclusions Use of ALND after NAC has significantly decreased over the past decade. This is most pronounced in cN+ disease at diagnosis with an increase in the use of SLN surgery after NAC. Additionally, in pN+ disease after NAC, there has been a decrease in use of completion ALND, a practice pattern change that precedes results from clinical trials.