BRCA2 and breast cancer: MPC: metastatic pancreatic cancer; PFS: progression-free survival; OS: overall survival; BRCA: breast cancer-associated; ATM: ataxia-telangiectasia mutated; PALB2: partner and localizer of BRCA2; FANCB: FA complementation group B; CHEK2: checkpoint kinase 2; IMRT: intensity-modulated radiotherapy; SD: stable disease