BRCA1 and breast cancer: Among TNBC stage I-III breast cancers with early (N = 134) and late (N = 66) recurrence, the most frequent alteration was PIK3CA (20.2% vs 33.3%), followed by BRCA1/2 (6.0% vs 9.1%), PD-L1 amplification (2.2% vs 3.0%), PALB2 (1.5% vs 0%), and ESR1 (0% vs 1.5%).