Evolution of Breast Cancer Treatment 2010-2023.

[BACKGROUND] With the introduction of targeted therapies and the de-escalation of surgical operations, we aimed to describe recent changes in breast cancer treatment.

[PATIENTS AND METHODS] The National Cancer Database was queried for patients with clinical stage I-III breast cancer from 2010 to 2023 who underwent surgery. Cochran-Armitage trend tests and the Kaplan-Meier method were used.

[RESULTS] We identified 1,769,438 patients; median age was 61 years, with clinical stage I (60.6%), stage II (32.7%), and stage III (6.7%). In total, 74.1% of patients had ER+/HER2-, 13.5% HER2+, and 12.3% ER-/HER2- disease. Most patients (62.7%) underwent breast-conserving surgery (BCS). Mastectomy rates declined from 42.3% in 2010 to 33.3% in 2023 (p < 0.001); within mastectomy, reconstruction rate increased (36.5% to 48.8%) as did contralateral prophylactic mastectomy rates (31.6% to 47.6%), both p < 0.001. Rates of axillary lymph node dissection (ALND) decreased (38.2% to 18.8%, p < 0.001). Omission of axillary surgery among clinical stage I patients increased (4.3% to 12.5%, p < 0.001). Rates of neoadjuvant chemotherapy increased overall and especially among ER-/HER2+ (30.4% to 70.2%, p < 0.001) and ER-/HER2- (25.5% to 64.8%, p < 0.001) subtypes. Use of neoadjuvant endocrine therapy in ER+/HER2- disease increased from 2.8% to 6.0%, p < 0.001. Use of radiation therapy in patients treated with BCS declined (87.8% to 80.1%, p < 0.001). The 10-year overall survival varied by clinical stage group and biologic subtype.

[CONCLUSIONS] Breast cancer care has evolved, with decreased use of ALND and increased use of reconstruction and of contralateral prophylactic mastectomy in patients undergoing mastectomy. Furthermore, there has been significant increase in neoadjuvant systemic therapy use, especially among HER2+ and ER-/HER2- biologic subtypes.