In multivariate Cox regression including tumor grade, ER status, PR status, HER2 status, and Ki-67 status as factors, PUM1 protein expression was shown to be an independent prognostic indicator of unfavorable survival regardless of these factors (HR = 3.816, 95% CI = 1.826–10.984, p = 0.013; Table 2). This evidence concerns the gene ESR1 and neoplasm.