NR4A1 and bone metastasis: Patients treated with radiotherapy were more likely to be young (under 60, 47.1% in the no-radiotherapy group vs. 57.0% in the radiotherapy group, P < 0.001), be hormone receptor-positive (64.6% vs. 73.5%, P < 0.001), have bone metastasis (52.5% vs. 62.8%, P < 0.001), be treated with breast-conserving surgery (31.5% vs. 37.2%, P = 0.005), and be married (44.8% vs. 49.5%, P = 0.025).