The clinical value of exhaled nitric oxide in patients with lung cancer

To investigate the clinical value of fractional exhaled nitric oxide (FeNO) in lung cancer patients.

A total of 172 healthy control subjects and 164 patients with histopathologically confirmed lung cancer were enrolled in this study. The FeNO measurements and pulmonary function tests were conducted in the Chinese PLA General Hospital. The recorded data included FeNO, the forced expiratory volume in one second (FEV₁ ), the forced vital capacity (FVC), FEV₁ /FVC, the FEV₁ (% predicted), the demographic characteristics, the presence of complications and the smoking status.

The patients with lung cancer had a significantly higher level of eNO than the healthy control subjects (33.85 ± 15.63 ppb, n = 163; 16.83 ± 4.17 ppb, n = 172; P < 0.01). The areas under receiver operating characteristic curves for eNO predicting airway inflammation in lung cancer subjects and healthy control subjects was 0.932 (95% confidence interval: 0.904-0.961). In the lung cancer group, the eNO levels in the squamous cell carcinoma, adenocarcinoma, small-cell lung cancer and lung carcinoid tumor groups were significantly different (P < 0.01). Lung cancer patients with a predicted FEV₁ % value <80% had a higher level of eNO than the patients with a predicted FEV₁ % value ≥80%.

The eNO levels in patients with lung cancer were higher than the normal level, especially in the patients with squamous cell carcinoma and small-cell lung cancer. The differences in eNO among the lung cancer subtypes were statistically significant. Measuring eNO will be helpful in diagnosing airway inflammation in lung cancer and in the classification of lung cancer.