One recent line of cancer research is currently directed to the study of growth factors. Of increasing interest is endothelin-1 (ET-1), a mitogenic factor already investigated in several human cancer cell lines, which has been found to participate in the development and progression of tumours. This peptide has an important role also in non-small-cell lung cancer (NSCLC) where ET-1 expression has been found in 100% of cell lines.
Objectives: The aim of this study was to measure ET-1 concentrations in the airways of patients with NSCLC using a completely non-invasive procedure--the breath condensate--and to verify the involvement of this peptide in the growth of lung tumours.
Methods: We enrolled 30 patients (17 men, median age 63 years; range 53-74) with histological evidence of NSCLC and 15 healthy controls (9 men, median age 59 years; range 52-70). ET-1 was measured in the exhaled breath condensate by means of a specific enzyme immunoassay kit.
Results: Higher concentrations of exhaled ET-1 were found in NSCLC patients (8.3 +/- 0.7 pg/ml) compared to controls (5.2 +/- 0.5 pg/ml, p < 0.0001). A statistically significant difference was observed between patients with distant metastases (stage IV) of NSCLC (8.9 +/- 0.6 pg/ml) and those with locoregional disease (stage I-III) (7.9 +/- 0.5 pg/ml). A significant reduction in ET-1 levels was found in 14 patients after surgical removal of the tumour either associated with or without adjuvant chemotherapy (6.3 +/- 0.5 vs. 7.9 +/- 0.4 pg/ml, p < 0.0001).
Conclusions: These findings suggest that the measurement of ET-1 in the breath condensate of patients with NSCLC could be proposed as a marker for early detection of NSCLC as well as for monitoring reduction or progression of the neoplasm in the follow-up of treated patients.
Copyright 2004 S. Karger AG, Basel