The high NLR remained a significant independent prognostic factor for overall survival among non-metastatic breast cancer patients after adjustment for the clinical factors of age, stage, grade, and combined ER/PR receptor status (HR = 2.12, 95% CI: 1.05–4.29) and additional adjustment for the patient factors of BMI and smoking history and the treatment factors of payer category, chemotherapy regimen, and radiation therapy regimen (HR = 2.27, 95% CI: 1.02–5.08). The gene discussed is ESR1; the disease is breast cancer.