Univariate Cox regression model analysis showed that older age (≥65 years old), single status, large-size tumor, lymph node metastasis, and mastectomy contributed to lower OS, while Asian or Pacific Islander and American Indian/Alaska Native race, ER positive, PR positive, and radiation therapy were associated with higher OS (Table 2). The gene discussed is ESR1; the disease is metastatic malignant neoplasm in the lymph nodes.