Loss of special AT-rich sequence-binding protein 1 (SATB1) predicts poor survival in patients with colorectal cancer.

AIM:Special AT-rich sequence-binding protein 1 (SATB1) is a cell type-specific matrix attachment region binding protein, functioning as a global genome organizer. This study aims to investigate the expression pattern and the prognostic value of SATB1 in colorectal cancer. METHODS AND RESULTS:Prospectively collected data were obtained and tissue microarrays were constructed from a cohort of 352 patients. SATB1 protein expression was evaluated by immunohistochemistry and scored by two independent investigators. SATB1 expression was predominantly nuclear in both normal and cancer tissues. Loss of SATB1 nuclear expression was seen in 22% of colorectal cancers compared to 1.5% of adjacent normal colorectal tissue, and was associated with worse overall survival (P = 0.02) independent of age and stage of disease (HR 2.48 with 95% CI 1.31-4.70). Loss of SATB1 expression was more evident in younger patients (P = 0.03), tumours with mucinous or signet ring histology (P = 0.0001) and poor differentiation (P = 0.005). SATB1 expression was associated with a survival advantage in patients with Dukes C tumours who received adjuvant chemotherapy. CONCLUSION:Loss of SATB1 nuclear expression correlates with poor survival and a less favourable response to adjuvant chemotherapy in colorectal cancer. The value of SATB1 in individualized colorectal cancer therapy warrants further evaluation.