Background: Luminal A breast cancer (BC) is considered a subtype with a good prognosis, but some poor prognostic factors can be identified, i.e. advanced stage and/or young age at presentation seem to be associated with higher risk of recurrence after neoadjuvant treatment (NAT). The importance of the progesterone receptor (PR) in Lum A BC prognosis has also been explored. Methods: We evaluated 2,248 patients with Lum A like BC (HER2-/estrogen receptor +/grade1-2) from 6 anthracycline-taxane based NAT trials (plus adjuvant endocrine therapy (ET) and radiotherapy if indicated). Combining tumor stage (AJCC Cancer Staging seventh), PR status, and age at baseline, we generated a score to divide Lum A like BC into 5 groups (Table). We used Kaplan Meier and uni/multivariate Cox regression analyses to explore the effect of the score on disease free (DFS) and overall survival (OS) and to evaluate its interaction with CPS+EG score (Mittendorf EA, JCO 2011), body mass index (BMI≤30/>30kg/m²), pCR (ypT0 ypN0), NAT density (conventional/dose-dense), and duration (24/18/≤12 weeks). Results: Mean DFS and OS decreased from score A to E (DFS: A 106.9 months, B 98.9, C 90.7, D 80.5, E 46.5; p< .001; OS: A 109.9 months, B 107.2, C 100.6, D 91.0, E 57.8; p< .001). Univar. analysis hazard ratios (HR) are displayed below. In multivar. analysis, our score independently predicted DFS (p< .001) and OS (p= .049). No interactions were observed (DFS: score*CPS+EG p= .440, s*BMI p= .347, s*pCR p= .462, s*density p= .350, s*duration p= .590; OS: s*CPS+EG= .734, s*BMI p= .784, s*pCR p= .999, s*density p= .870, s*duration p= .999). Conclusions: Using characteristics available in daily practice before treatment, we developed a score to identify Lum A like BC patients with poorer prognosis, despite NAT and ET, who are candidates for more aggressive NAT or additional postNAT in future studies.