Elevated plasma thymosin-α1 levels in lung cancer patients

Objective: Prothymosin-α, the precursor of thymosin-α1, may play a role in cell proliferation, and the plasma level of thymosin-α1 may reflect the degree of proliferation of the tumor cells. Methods: Recently, a new sandwich immunoradiometric assay for thymosin-α1 was developed using monoclonal and polyclonal antibodies. In this investigation, we used this assay to measure plasma and tissue level of thymosin-α1 in 131 lung cancer patients. Results: We found that the mean plasma thymosin-α1 levels in lung cancer patients were higher than in normal individuals (P<0.001). However, half of the patients showed normal levels. Thymosin-α1 levels correlated neither with the stage nor pathological subtype of the lung cancer, and did not decrease significantly in the 4 weeks after the resection of the tumor. Thymosin-α1 levels of lung cancer patients with another cancer were higher than those without evidence of other cancers (P=0.03). Survival of patients with normal levels of plasma thymosin-α1 was significantly better than that with higher levels (P=0.04). Conclusions: The plasma level of thymosin-α1 may be used as a marker for the prognosis of lung cancer patients. Further investigations are warranted to determine its role in the lung cancer.