ABSTRACT
Background: There is an interest in performing de-escalating axillary surgery after neoadjuvant chemotherapy (NAC). However, the significance of residual axillary node disease after NAC has not been well studied. Objectives: To investigate the pathological residual axillary lymph node tumor burden (ypN) of patients with initial clinical nodal stage cN0-1 breast cancer after NAC and determine its prognostic value. Design: Initial cN0-1 breast cancer patients who received NAC followed by axillary surgery at the First Hospital of Jilin University and the First Affiliated Hospital of Xi'an Jiaotong University between January 2011 and December 2019 were included. Methods: Survival outcomes were compared according to different clinical and pathological stage and nodal response to NAC. The main outcomes were disease-free survival (DFS) and overall survival (OS). Factors associated with survival were defined by Cox regression analysis. Results: A total of 911 patients were included, among whom 260 had cN0 and 651 had cN1 tumors. After NAC, 410 patients were ypN0, and another 501 were ypN+. The median follow-up time was 63 months. There was no significant difference in DFS or OS between the cN0 and cN1 groups in hormone receptor positive (HR+)/human epidermal growth factor receptor 2 positive (HER2+) and HR-/HER2- subtypes; instead, ypN status was significantly related to DFS and OS. In HR+/HER2- subtype, both cN and ypN stages did not show significant survival differences, but the ypN number and the nodal response to NAC showed significant prognostic value (p < 0.05). Among HR-/HER2+ patients, all cN status, ypN status, ypN number, and nodal response were significantly associated with survival (p < 0.05). Furthermore, tumor biology, axillary surgery, ypN status, pathological tumor size, and radiotherapy were independent prognostic factors for DFS and OS. Conclusion: The ypN status after NAC provide more prognostic information than the initial cN stage in cN0-1 patients, and the surgical axillary staging after NAC may have high clinical value.
ABSTRACT
Various novel HER2-targeted antibody-conjugated drugs (ADCs) have shown satisfactory antitumor activity in HER2-low-positive breast cancer (BC). It is urgent to clarify whether HER2-low-positive tumors have unique biological behavior and should be considered a new molecular subtype. We screened eligible BC patients and collected relevant information at the First Hospital of Jilin University and the First Affiliated Hospital of Xi'an Jiaotong University from January 2010 to December 2020. A total of 1027 patients were included in our study cohort, and 66.0% (678/1027) had HER2-low-positive tumors. Compared to HER2-zero patients, HER2-low-positive patients tended to have more lymph node metastasis, a larger proportion of hormone receptor (HR)-positive tumors, and a lower proliferation rate (Ki-67). The pathologic complete response (pCR) rate of HER2-low-positive patients was lower than that of HER2-zero patients (19.3% vs 26.1%), especially in the HR-positive subgroup (12.00% vs 20.29%). However, multivariate logistic regression analysis showed that HER2 status was not an independent factor for predicting pCR. HER2-low-positive patients had a higher overall survival (OS) rate in the HR-positive subgroup. The Cox regression model analysis suggested that HER2-low-positive status did not statistically significantly affect the survival outcomes, regardless of disease-free survival (DFS) (P=0.308) or OS (P=0.066). In conclusion, HER2-low-positive tumors have unique clinical and pathological characteristics, with a lower pCR rate in the HR-positive subgroup and better survival in the HR-negative subgroup compared to HER2-zero tumors. However, the effect of HER2-low-positive status on pCR or survival outcomes was not statistically significant.
