Objective: The objective of this pilot study is to evaluate the ability of lung ultrasound to provide signs of suspicion of lung cancer in patients with respiratory symptoms related to a real-world setting.

Patients and methods: This is a monocentric pilot study. All patients belonging to the Internal Medicine ward with respiratory symptoms including cough, chest pain or dyspnea were recruited. Patients with previous diagnoses of respiratory diseases were excluded. An ultrasound and chest radiography (CR) were performed by expert operator. Computed tomography was carried out in case of discrepant imaging or suspect of cancer. The gold standard was the discharge diagnosis.

Results: The final diagnosis included 51 cases of lung cancer, and 386 other diagnoses, which included pneumonia, heart failure, chronic obstructive pulmonary disease (COPD), tuberculosis, pneumothorax or fibrosis/restrictive syndrome. Consolidation areas were found in 75.4% of patients diagnosed with lung cancer, in 51% of all other diseases. Single sides pleural effusion was found in 52.9% of lung cancer (4.2% in the absence of pathology vs. 25.1% other diagnoses. A significantly higher prevalence of pleural pain and lactate were observed in cancer patients (23.5% and 34.7%, respectively). A receiver operating characteristics curve (ROC) showed a high LUS accuracy for both operators (LUS-I AUROC: 0.855 [95% CI: 0.793-0.917]; p<0.001 and LUS-II AUROC: 0.838 [95% CI: 0.774-0.902]; p<0.001), with a sensitivity and specificity of 92.2% and 87.8%, respectively.

Conclusions: The findings showed the lung ultrasound might be useful in the diagnosis of lung cancer in clinical practice. These data need to be supported by a large clinical trial.