Evaluation of whether adjuvant chemotherapy can be safely omitted for older female patients with ER-positive, HER2-negative N1 breast cancer: a study based on the SEER database - Lv, Minhao; Yuan, Peng; Ma, Youzhao; Tian, Peiqi; Chen, Xiuchun; Liu, Zhenzhen (Annals of Translational Medicine; Vol 9, No 13 (July 14, 2021): Annals of Translational Medicine, 2021)