The univariate analysis revealed that age (P = 0.048), tumor size (P = 0.013), histologic grade (P = 0.003), HR status (P = 0.004), and postoperative endocrine treatment (P < 0.001) were prognostic factors affecting DFS in patients with HER2-negative patients, and multivariate analysis found age (HR [95% CI] = 0.950 [0.928, 0.972], P < 0.001), HR status (HR [95% CI] = 3.342 [1.658, 6.736], P = 0.001), and postoperative endocrine therapy (HR [95% CI] = 0.048 [0.048, 0.023], P < 0.001) were independent prognostic factors influencing DFS in HER2-negative patients. This evidence concerns the gene ERBB2 and neoplasm.