Screening tests refer to tests or examinations performed to investigate a disease without the presence of symptoms. Since lung cancers often spread outside the lungs before causing symptoms, an effective screening program for early diagnosis of lung cancer can save many lives.
Chest X-rays and sputum cytology (microscopic examination for cancer cells in sputum) have been used for many years. However, unfortunately, these tests do not diagnose the disease early enough to offer the patient a chance for treatment. Therefore, lung cancer screening is not routinely applied to the general public or even to high-risk smokers.
Recent studies have shown that spiral or helical low-dose computed tomography (CT) is successful in early lung cancer screening among smokers. However, whether this method is life-saving has not yet been definitively established, and studies are ongoing. New tests that detect DNA (the hereditary material in cell nuclei) changes in bronchial cells for early diagnosis of lung cancer have been developed, but none of these methods are currently used routinely.
