Associations of TP53- and/or PIK3CA mutated HR-positive, invasive ductal breast cancers (IDBC) of the METABRIC collection with distant recurrence risk (DRR) and time-to-recurrence (TTR).

e12542Background: PIK3CA and TP53 count amongst the most frequently mutated genes in LumBCa. In the study presented here we worked with ER and/or PR positive, HER2 negative IDBCs from METABRIC collection (N=1.104) to assess the associations between PIK3CA- or TP53 mutation status and DRR or TTR. Methods: Clinical-pathologic and genomic variables (oncogenic mutations/CNVs, gene expression) were used to develop a parsimonious prognostic model for disease free survival using a robust, innovative statistics approach combined with cross-validation methodology. The predictive accuracy of the different sets of information was assessed using time-dependent ROC curves. Results: With the exception of a higher frequency of PIK3CA mutations (H1047R, E542K, E545K) in late recurring (58%) compared to early recurring tumors (40%), no other specific distribution patterns or associations with specific subpopulations were observed. Consistent with data from the literature [1, 5, 6 ] the relapse-free survival rate amongst p...