乳腺癌新辅助化疗（NAC）具有确定治疗现场的体内反应、实施更保守的手术以及促进肿瘤生物学的了解的优势。新辅助化疗后的病理完全缓解（pCR）是改善总体生存率的预测因子。然而，一些患者在乳房和腋窝淋巴结对新辅助化疗的反应上存在不一致性。本研究旨在确定与仅乳房达到pCR而腋窝淋巴结未达到pCR的相关因素，并探索潜在的临床意义。利用国家癌症数据库，找到了2004年至2017年之间被诊断为临床T1-4，N1-3乳腺癌的患者。患者经历了新辅助化疗后进行乳腺癌手术切除和腋窝淋巴结手术。采用多变量分析来确定与病理反应不一致相关的临床和病理因素。总计符合纳入标准的患者有13,934例，其中4292例（30.8%）患者在最终病理学检查中乳房达到了pCR，但腋窝淋巴结未达到pCR。在调整协变量后，与乳房达到pCR的乳腺癌患者腋窝反应不一致较高的因素包括年龄较大（≥ 54岁）、在社区医疗机构接受治疗、T1肿瘤、激素受体阳性、HER2阴性、低分级肿瘤和cN2/3疾病。乳房和腋窝pCR之间的不一致并不少见，可能与一些与患者相关的因素和肿瘤特征有关，这些因素影响了腋窝对新辅助化疗的反应。需要进一步研究不同对NAC的反应，以更好地了解这一现象的机制，并确定这些发现如何影响治疗。© 2023年。外科肿瘤学学会。

Neoadjuvant chemotherapy (NAC) for breast cancer has the advantage of determining in vivo response to treatment, enabling more conservative surgery, and facilitating the understanding of tumor biology. Pathologic complete response (pCR) after NAC is a predictor of improved overall survival. However, some patients demonstrate a discordant response to NAC between the breast and axillary nodes. This study was designed to identify factors that correlate to achieving a breast pCR without an axillary node pCR following NAC and explore the potential clinical implications.The National Cancer Database was used to identify patients diagnosed with clinical T1-4, N1-3 breast cancer between 2004 and 2017. Patients underwent NAC followed surgical resection of the breast cancer and axillary node surgery. Multivariable analyses were used to identify clinical and pathologic factors associated with discordant pathologic response.In total, 13,934 patients met the inclusion criteria. Of these, 4292 (30.8%) patients demonstrated a breast pCR without a corresponding axillary pCR on final pathology. After adjusting for covariates, factors associated with higher discordance between axillary response in our cohort of breast pCR patients included older age (≥ 54), treatment at a community facility, T1 tumors, HR-positive, HER2 negative, low-grade tumors, and cN2/3 disease.Discordance between breast and axillary pCR is not infrequent and may be related to a number of patient-related factors and tumor characteristics impacting nodal response to NAC. Further investigation into differing responses to NAC is warranted to better understand the mechanism of this phenomenon and to determine how these findings may influence treatment.© 2023. Society of Surgical Oncology.