Serine threonine tyrosine kinase 1 is a potential prognostic marker in colorectal cancer

Background: Aberrant expression of serine threonine tyrosine kinase 1 (STYK1) has been reported in several human malignancies including colorectal cancer (CRC). However, the prognostic significance of STYK1 expression in CRC remains unknown. Methods: STYK1 protein expression in paraffin-embedded CRC specimens was determined immunohistochemically. The correlation of STYK1 expression with clinicopathologic features was assessed in a cohort containing 353 patients with primary CRC. Kaplan-Meier and Cox proportional regression analyses were used to evaluate the association between STYK1 expression and patients' survival. Results: STYK1 expression was frequently up-regulated in CRC clinical samples at the protein levels and was significantly associated with tumor differentiation grade (p = 0.030), lymph node metastasis (p = 0.004), TNM stage (p = 0.007) and patient death (p < 0.001). Kaplan-Meier analysis indicated that patients with high intratumoral STYK1 expression had a significantly shorter disease-specific survival (DSS) than those with low expression (p < 0.001). Importantly, high levels of STYK1 protein predicted poor DSS for both stage II (p < 0.001) and stage III (p = 0.004) patients. Furthermore, multivariate analyses revealed that STYK1 protein expression was an independent prognostic indicator for both stage II (hazard ratio [HR], 2.472; p = 0.001) and stage III (HR, 2.001; p = 0.004) patients. Conclusions: Our results suggest that increased STYK1 protein expression correlates with disease progression and metastasis and may serve as a predictor of poor survival in CRC.