Screening is looking for cancer before a person has any symptoms. This can help find cancer at an early stage when it may be easier to treat. Lung cancer may have spread by the time a person has symptoms. One reason lung cancer is so serious is because it usually is not found until it has spread and is more difficult to treat.
Screening may provide new hope for early detection and treatment of lung cancer. Scientists study screening tests to find those with the fewest risks and most benefits. They look at results over time to see if finding the cancer early decreases a person's chance of dying from the disease.