Screening for lung cancer by routine chest X-rays gets the thumbs down from the American Cancer Society. See this CBS News report. - Well that's another bit of good news today! - The fewer damaging doses of ionising radiation people get, the better. I am not in favour of screening by X-rays.
"The 13-year study tracked more than 150,000 Americans between the ages of 55 and 74 and found those who had four annual chest X-ray screenings were just as likely to die of lung cancer as those who didn't get screened. Whether they smoked didn't matter. Screening refers to routine tests in people without symptoms. Doctors still support chest X-rays for diagnosing people with lung cancer symptoms, including coughing up blood and a persistent cough."