High cytoplasmic expression of SALL4 predicts a malignant phenotype and poor prognosis of breast invasive ductal carcinoma.

Sal-like 4(SALL4) is significant for maintaining self-renewal and pluripotency in embryonic stem cells, cancer cells and perhaps even cancer stem cells. The expression of SALL4 has been recorded in various kinds of cancers and is deemed to have a clinical value for diagnosis. However, little information on SALL4 expression has been illustrated in breast cancer. In this study, the expression of SALL4 was scrutinized by immunohistochemical analysis in breast invasive ductal carcinoma in a large cohort of 160 patients. High cytoplasmic expression of SALL4 was detected in breast cancer tissues compared with normal adjacent tissues. High SALL4 expression was associated with advanced tumor invasion (p = 0.019), lymph node stage (p = 0.027), ER (p = 0.030), PR (p = 0.037), HER2 (p = 0.019) and TNBC (p = 0.007) in overall patients. Interestingly, in Kaplan-Meier analysis, breast cancer patients with high expression of SALL4 demonstrated a worse OS. Both univariate and multivariate analysis illustrated that examination of SALL4 was of great prognostic value in OS. Thus, our data showed that high cytoplasmic expression of SALL4 was considered to be an independent prognostic indicator for breast invasive ductal carcinoma.