SIRT1 and neoplasm: Elevated SIRT1 level was associated with tumor stage [Relative Risk (RR) = 1.299, 95% CI: 1.114-1.514, <i>P</i> = 0.0008], lymph node metastasis (RR = 1.172, 95% CI: 1.010-1.360, <i>P</i> = 0.0363), and distant metastasis (RR = 1.562, 95% CI: 1.022-2.387, <i>P</i> = 0.0392).