8-Isoprostane in exhaled breath condensate of patients with non-small cell lung cancer: the effect of chemotherapy.

AIM The aim of the study was to evaluate the exhaled breath condensate (EBC) levels of a valid oxidative stress marker, 8-isoprostane, before and after chemotherapy, in patients with non small cell lung cancer (NSCLC) in correlation with the extent of the disease and response to treatment. PATIENTS AND METHODS Forty-five patients with inoperable NSCLC were initially enrolled in the study. Twenty-nine of them were finally evaluated in regards to 8-isoprostane levels in EBC before and after chemotherapy. RESULTS 8-Isoprostane levels were significantly lower after chemotherapy (p=0.014). Further analysis showed that the differences were mainly attributed: a) to the extent of the disease, with patients diagnosed with up to locally advanced disease (stages IB-IIIB) having significantly lower EBC 8-isoprostane levels post-chemotherapy (p=0.031); and b) to the response to treatment, with patients evaluated with partial response to treatment having significantly lower EBC 8-isoprostane levels post-chemotherapy (p=0.02). CONCLUSION In this prospective study, we showed that 8-isoprostane might represent a biomarker in NSCLC, reflecting both response to chemotherapy, as well as the extent of the disease.