A single-institution retrospective study explores whether immune markers in the peripheral blood can anticipate the response to neoadjuvant treatment with pembrolizumab plus chemotherapy in triple-negative breast cancer (TNBC). A simple blood-test measure, the neutrophil-to-lymphocyte ratio, emerges as a possibly accessible indicator.
What was already known
Neoadjuvant systemic therapy is the standard of care for high-risk early TNBC. Although pathological complete response (pCR) is strongly associated with improved survival, reliable and accessible predictors of response remain scarce.
What this work adds
This is a single-institution retrospective study in which 60 patients with stage II-III TNBC received neoadjuvant systemic therapy according to the KEYNOTE-522 regimen, followed by curative-intent surgery. Before treatment, the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR) and tumour-infiltrating lymphocyte (TIL) levels were assessed. Associations with pCR were analysed using logistic regression models.
Main results
Thirty-six patients (60.0%) achieved pCR. In univariate analysis, a low NLR, high TILs and histological type were significantly associated with pCR, whereas PLR was not. Multivariate analysis identified a low NLR and histological type as independent predictors of pCR. Patients with both a low NLR and high TILs showed the highest pCR rate.
What it means
The authors conclude that NLR may be a simple and accessible predictor of pCR in patients with TNBC receiving neoadjuvant pembrolizumab plus chemotherapy, and that combining peripheral blood immune markers with intratumoral immune parameters may enhance treatment stratification. Given its retrospective nature and limited size, this is a signal to be confirmed in larger cohorts before being used in clinical decisions.
A breast-unit perspective
Response markers based on routine blood tests are attractive because they would not require additional complex testing. Even so, their practical usefulness would depend on validation in prospective studies using homogeneous criteria across centres.
Reference: Fujimoto A, Ichinose Y, Matsuura K, Mikami E, Inohana W, Kurosawa T, et al. Neutrophil-to-Lymphocyte Ratio Predicts Pathological Complete Response in Triple-Negative Breast Cancer Treated With Neoadjuvant Pembrolizumab Plus Chemotherapy. Clinical Breast Cancer, 2026. DOI/link
