Objective: This study aimed to investigate the
clinical molecular characteristics in patients with human epidermal growth factor
receptor 2 (HER2)-negative breast cancer and axillary lymph node metastasis and
explored the related factors of the neoadjuvant chemotherapy (NAC) response.
Methods: The data of 185 patients with HER2-negative breast cancer and
axillary lymph node metastasis who were treated in the Department of Breast
Center of the Affiliated Hospital of Qingdao University from July 2017 to July
2021 were retrospectively analyzed. The clinical features and the related factors
for the responses of the primary tumor and axillary lymph node metastasis to NAC
were analyzed. Statistical analysis was conducted using the SPSS 26.0 statistical
software. Univariate analysis was conducted using the test, and
multivariate analysis was conducted using logistic regression analysis.
Results: The differences in estrogen receptor (ER), progesterone
receptor (PR), and Ki67 among the three HER2-negative subgroups (the
immunohistochemistry (IHC)0 group, IHC1+ group, and IHC2+/in situ
hybridization– group) were statistically significant (p 0.05).
Univariate analysis revealed that the differences in the tumor stage, ER, PR, and
Ki67 among the groups based on the response of the primary tumor to NAC were
statistically significant (p 0.05), and the differences in ER, PR,
and Ki67 among the groups based on the response of axillary lymph node metastasis
to NAC were statistically significant (p 0.05). Multivariate
analysis revealed that the difference in Ki67 among the groups based on the
response of axillary lymph node metastasis to NAC was statistically significant
(p 0.05). Conclusions: When the expression level of
HER2-negative IHC increases, the positive rates of ER and PR increase. A smaller
tumor, negative ER, negative PR, and a Ki67 level 30% indicate a good effect
of NAC for primary tumors. Negative ER, negative PR, and a Ki67 level 30%
indicate a good effect of NAC for axillary lymph node metastasis. Therefore, Ki67
may be an independent factor affecting the efficacy of NAC for axillary lymph
node metastasis.