ERBB2 and neoplasm: Multivariate analysis was performed using Cox’s proportional hazard method, and included tumour size, tumour grade, tumour stage, NPI, ER status, PgR status, HER2 status and vascular invasion, both nuclear DKK1 and cytoplasmic DKK1 expression was not associated with patient survival in these models (hazard ratio (HR) = 0.834, 95% confidence interval (CI) = 0.625–1.113, P = 0.217, and HR = 0.934.