Abstract
BACKGROUND: Taxane-carboplatin-based neoadjuvant chemotherapy (NAC) improves the pathological complete response (pCR) rate in human epidermal growth factor receptor 2 (HER2)-negative breast cancer. However, its effect on long-term survival remains unclear. Reliable prognostic biomarkers are needed to guide personalized postoperative strategies. OBJECTIVES: To evaluate the prognostic significance of the platelet-to-lymphocyte ratio (PLR) and to construct a predictive model for overall survival (OS) in this clinical setting. DESIGN: This was a retrospective, multicenter cohort study involving an internal development cohort and an external validation cohort. METHODS: We retrospectively analyzed 178 HER2-negative breast cancer patients treated with taxane-carboplatin NAC at Fudan University Shanghai Cancer Center (FUSCC). The optimal PLR cutoff (129.75) was identified via receiver operating characteristic (ROC) analysis. Logistic regression assessed the association between PLR and pCR, and multivariate Cox regression evaluated its prognostic value for OS. A nomogram incorporating PLR, estrogen receptor (ER) status, and clinical stage was built using the FUSCC cohort. The nomogram was externally validated in 34 patients from Fujian Cancer Hospital. RESULTS: Among the 178 patients, 94 (52.8%) had high PLR and 84 (47.2%) had low PLR. High PLR was not independently associated with pCR (odds ratio = 1.006; 95% confidence interval (CI): 0.999-1.013; p = 0.079). However, in non-pCR patients, high PLR was significantly linked to poorer OS (p = 0.001). Multivariate analysis identified high PLR (hazard ratio = 5.718; 95% CI: 1.664-19.646; p = 0.006), clinical stage III disease, and ER positivity as independent OS predictors. The nomogram integrating these factors demonstrated strong predictive performance in both cohorts. CONCLUSION: This is the first study to evaluate PLR as a prognostic marker in HER2-negative breast cancer treated with taxane-carboplatin NAC. High PLR was independently associated with poorer survival. The proposed nomogram provides a practical tool for postoperative risk stratification and personalized care.