Performance evaluation of detecting circulating tumor cells and tumor cells in bronchoalveolar lavage fluid in diagnosis of peripheral lung cancer

Lung cancer is the malignancy with the highest morbidity and mortality in the world. Approximately 18% of cancer deaths are associated with lung cancer (1,2). The 5-year survival rate of lung cancer patients is low which is frequently associated with late diagnosis (3). Therefore, early diagnosis of lung cancer is of clinical importance for improving long-term prognosis. High resolution computed tomography (HRCT), which can display the morphology and location of small peripheral nodes, is the most common technique for early diagnosis of lung cancer. However, a CT examination confers limited value for distinguishing benign lung lesion from malignancy. Although a high magnitude of lung cancer-related tumor marker (e.g., CEA, CA125, and NSE) usually suggest a lung cancer diagnosis, the sensitivity and specificity are not yet high enough for early screening and diagnosis of lung cancer in clinical practice