Fig. 3

OS of MBC patients displayed as Kaplan–Meier curves according to RT for different patient subgroups: a age ≥ 60 years and age < 60 years subgroup with or without RT after PSM. b Tumor size ≤ 5 cm and a > 5 cm subgroup with or without RT after PSM. c N0 subgroup with or without RT before PSM. d N0 subgroup with or without RT after PSM. e N1 subgroup with or without RT after PSM