Introduction: Although known to hold prognostic value, PR status is not used to discriminate luminal A from luminal B HER2 negative breast cancers. We will here assess whether PR (and also detection mode) is an independent prognostic variable in luminal HER2 negative breast cancer and whether the prognostic value of PR is grade dependent. Patients and methods: Primary operable breast cancer patients diagnosed between 1/1/2000 and 31/12/2009 treated in UZ Leuven were retrieved from the prospectively managed database (n = 4318). Her-2 status was missing in 93 and ER/PR in 2 patients. Of the remaining patients, 3330 were luminal (ER and/or PR positive) HER2 negative (full cohort details: Brouckaert O., et al. Ann Oncol. 2012 Apr 6). Missing values were observed in 137 patients (4.1%), and these were imputed using ‘multivariate imputation by chained equations’. A competing risks proportional hazards model was used for multivariable analysis (includes age, size, grade, screening, palpability, nodal status, histology, type of surgery, radiotherapy, endocrine and chemotherapy) of distant metastasis free interval (DMFI) and breast cancer specific survival (BCSS). We used a predefined set of predictors, investigated non-linearity of the predictor effects, checked the proportional hazards assumption, and tested for interactions with grade. Results: Median follow-up was 76 months and 5-year survival probability 93%. PR is an independent prognostic variable but this is grade dependent for DMFI, but not for BCSS (interaction p = 0.15), although PR positivity was mainly protective for grade 3 breast cancers again (table 1). Palpability is a strong prognostic variable for DMFI and BCSS and was strongly correlated with screen detection (yes/no) and here, we found no evidence of grade dependency. Conclusion: PR status and palpability may further refine prognosis of patients with luminal HER2 negative breast cancers. For PR, prognostic value is grade dependent, but for palpability, this is grade independent. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-19.