SAA1 and metastatic neoplasm: All these known effects of SAA in tumor invasion and metastasis may explain our findings that significantly higher concentrations of SAA were observed in patients with lymph node or distant metastatic disease, and patients with an elevated level of SAA (≥ 8.0 mg/L) had significantly lower 5-year survival rate than those with non-elevated SAA (< 8.0 mg/L).