Plasma transforming growth factor-β1 reflects disease status in patients with lung cancer after radiotherapy: A possible tumor marker

Purpose: To determine the frequency with which elevated plasma transforming growth factor-β1 (TGFβ1) concentrations occur in lung cancer patients, to determine the kinetics of TGFβ1 expression during and after radiotherapy and to correlate plasma TGFβ1 levels with disease status after treatment. Materials and methods: Plasma samples were obtained before, during and after radiotherapy in 54 patients with lung cancer and 20 normal controls. Plasma TGFβ1 levels were measured using an enzyme-linked immunosorbent assay. Results: Baseline TGFβ1 levels in lung cancer patients and normal controls were 13.0 ± 2.5 and 4.4 ± 0.3 ng/ml, respectively. Elevated TGFβ1 were found in 50% (27/54) of lung cancer patients. During radiation therapy plasma TGFβ1 levels declined, however, by the completion of treatment the mean TGFβ1 level had not normalized in patients with lung cancer. The TGFβ1 level at last follow-up correlated with disease status in those patients with an increased pretreatment plasma level. Three of four patients with no evidence of cancer had normal follow-up TGFβ1 levels, compared to 2/16 patients with residual or recurrent tumor (P = 0.02). Conclusions: Elevated plasma TGFβ1 levels occur frequently in patients with lung cancer. In those patients with an elevated plasma TGFβ1 level at diagnosis, monitoring this level may be useful in detecting both disease persistence and recurrence after therapy.