RecurIndex-derived molecular features associated with total pathological complete response in triple-negative breast cancer: An exploratory prospective cohort study with single-cell transcriptomic contextualization

Background Reliable biomarkers for predicting neoadjuvant chemotherapy (NAC) response in triple-negative breast cancer (TNBC) remain limited. We explored whether RecurIndex-derived molecular features were associated with total pathological complete response (tpCR).Methods Seventy-four patients with TNBC treated with dose-dense NAC were analyzed. Associations between RecurIndex risk scores, 18 core genes, and tpCR were assessed using logistic regression and ROC analyses. Clinical–molecular models were internally validated by bootstrap resampling. Public single-cell RNA-seq data were used for biological contextualization.Results Twenty-nine patients (39.2%) achieved tpCR. The distant recurrence score, was significantly associated with tpCR. OBSL1, BLM, and CCR1 were identified as candidate tpCR-associated genes. The model combining OBSL1, BLM, and clinical nodal stage achieved an AUC of 0.838 and an optimism-corrected AUC of 0.799.Conclusions RecurIndex-derived molecular features were associated with tpCR in TNBC. These exploratory findings warrant validation in independent cohorts.