Univariate analysis revealed that patients with younger age (<60 years) (P < 0.0001), negative progesterone receptor expression (P = 0.0028), higher Ki67 expression levels (P < 0.0001), and absence of lymph node metastasis (P < 0.0001) were more likely to benefit from pyrotinib treatment. Here, MKI67 is linked to metastatic malignant neoplasm in the lymph nodes.