Background: Adding taxanes to standard anthracycline-based adjuvant therapy improves survival outcome in node-negative breast cancer (BC) patients (pts) with high risk of recurrence. Due to the small magnitude of the benefit and to avoid toxicity, biomarker analyses aimed to identify subpopulations benefiting the most from taxanes are warranted. Methods: After surgery, 1,925 node-negative BC pts with at least one high-risk factor for recurrence (St. Gallen 1998 criteria) were randomly assigned to receive 6 FAC cycles or 4 FAC cycles followed by 8 weekly paclitaxel doses (FAC-wP); 108 out of the 181 HER2+ pts did not receive trastuzumab. With a median follow-up of 63.3 months, 93% and 90.3% of pts receiving FAC-wP or FAC, respectively, remained disease free (hazard ratio [HR]: 0.73; 95% CI: 0.54-0.99; log-rank p= 0.04; Martin JCO 2013). We performed central immunohistochemistry (IHC) for ER, PR, Ki-67 and HER2/FISH; pts were grouped in intrinsic BC subtypes according to the Prat et al. classification (JCO 2012): Luminal A: RE+, PR>20%, HER2-, Ki67<14%; Luminal B1: RE+, HER2-, PR≤20% and/or Ki67≥14%; Luminal B2: RE+, PR+/-, HER2+; HER2: RE-, PR-, HER2+; TN: RE-, PR-, HER2-. We report here the correlation between these variables and Distant Metastases-Free Survival (DMFS). Cox regression and log-rank test were used for analysis. Results: Central biomarker expression and subtype classification is currently available for 1,084 and 946 pts, respectively. DMFS in the 1,084 pts were 97.8% vs 94.8% (HR: 0.52; 95% CI: 0.28-0.97; p=0.035). In the univariate analysis, FAC-wP therapy, ER and PR positive status, low Ki67 proliferation and Luminal A and B1 subtypes were significantly associated with better DMFS. Absence of PR and Luminal B1 were predictive for FAC-wP benefit. The multivariate analysis showed that intrinsic subtype classification was predictive of DMFS (p=0.010). Conclusions: Our study suggests that IHC-based intrinsic subtypes provide prognostic value and could identify a subpopulation of node-negative BC pts (the luminal B1) who obtains more benefit from FAC-wP adjuvant therapy.