Elevated serum transforming growth factor beta 1 level in primary lung cancer patients with finger clubbing

The mechanism causing finger clubbing in patients with lung cancer (LC) is still unclear. We compared age, cigarette consumption, data on blood gas analysis and pulmonary function tests among patients with LC with clubbing (n = 30) and without clubbing (n = 28) and among patients with pulmonary emphysema (PE) with (n = 11) and without clubbing (n = 17). We also examined serum concentrations of transforming growth factor beta 1 (TGF beta 1) and insulin-like growth factor-I (IGF-I) in the patients and healthy volunteers (n = 21). There were no differences in age or cigarette consumption. LC groups showed normal levels of Pao2 and Paco2, suggesting that neither hypoxaemia nor hypercapnia caused clubbing in these patients. The level of serum TGF beta 1 in patients with LC with clubbing was significantly higher than in other groups (P < 0.005), whereas levels of IGF-I did not differ among the groups. Our data suggest that TGF beta 1 may play a role in the mechanism of clubbing in patients with LC.