Plasma level of transforming growth factor β1 measured from the azygos vein predicts prognosis in patients with esophageal cancer

Purpose: Transforming growth factor (TGF)-beta regulates cell growth inhibition. When tumor cells lose their sensitivity to TGF-beta growth inhibition, the excess TGF-beta that results may act on tumor cells to facilitate tumor development. Previously, we have shown that an elevated systemic TGF-beta1 level is not related to tumor progression in esophageal cancer (Y. Fukai et al., Int J Cancer 2003;104: 161-6). We considered that systemic inflammation or chronic disease, in addition to the tumor, may influence the plasma TGF-beta level. Therefore, we examined the hypothesis that the plasma TGF-beta level measured from the azygos vein would independently predict tumor progression and prognosis in patients with esophageal cancer. Experimental Design: Fifty-seven plasma samples were obtained intraoperatively from the azygos vein in patients with esophageal cancer. ELISA was used to quantify the plasma TGF-beta1 levels, which were correlated with pathological features and patient survival. Results: The mean plasma TGF-beta1 level measured from the azygos vein of esophageal cancer patients was 5.09 +/- 0.48 ng/ml (mean +/- SE). The survival rates of patients with a high TGF-beta1 level (defined as a level above the 4.6 ng/mI level of normal controls) in the azygos vein were significantly lower than those of patients with a low TGF-beta1 level (P = 0.0317). Moreover, the TGF-beta1 level in the azygos vein was an independent prognostic factor for overall survival (P = 0.0474). Conclusions: The level of plasma TGF-beta1 measured from the azygos; vein is an independent predictor in patients with esophageal cancer and may reflect tumor progression more specifically because the azygos vein is responsible for venous return from the esophagus.