They exhibited tumours with significantly lower grades (grade 1-2: 38.3% vs 4.2% for AR + /FOXA1- vs 9.8% for AR-; p < 0.001), a more frequent lobular histology (10.2% vs 0% for AR + /FOXA1- vs 1.6% for AR-; p = 0.001) and PIK3CA mutations (p < 0.001; exon 9: 12.7%, exon 20: 19.1%), a lower frequency of basal-like phenotype (48.8% vs 66.7% for AR + /FOXA1- vs 74.0% for AR-; p < 0.001), BRCA1 promoter methylation (4.8% vs 25.0% for AR + /FOXA1- vs 35.6% for AR-; p < 0.001), PTEN defects (p = 0.026) and PD-L1 expression [for both tumour cell membrane (p = 0.009) or TIL staining (p = 0.015)]. This evidence concerns the gene PIK3CA and neoplasm.