Achieving pathological complete response (pCR) after NAT is associated with improved event-free survival (EFS), but benefits vary widely, underscoring the need for predictive biomarkers.<h4>Objective</h4>To evaluate the association between baseline hemoglobin (Hb) levels and pCR and EFS in female breast cancer patients from Western Guangdong, China.<h4>Method</h4>This retrospective study included 404 invasive breast cancer patients who received NAT between 2014 and 2024. The gene discussed is GSTM1; the disease is invasive breast carcinoma.