PGR and breast cancer: Studies investigating mortality adjusted for age [57,58,59], mutation status [57,59], tumour size [59,89], nodal status [59,89], oestrogen receptor status [59,89], progesterone receptor status [89], HER2 receptor status [89], BC treatment (chemotherapy [59,89]/surgery [59]/tamoxifen [59,89]) and centre [57,58].