RATIONALE: New imaging procedures such as spiral CT may improve the ability to detect lung cancer in patients who are at high risk for the disease.

PURPOSE: Randomized clinical trial to compare the effectiveness of a spiral CT scan with that of a chest x-ray in detecting lung cancer in patients who are at high risk for the disease.

OBJECTIVES: I. Compare the efficacy of screening spiral CT scan and screening chest x-ray in detecting lung cancer in current or former smokers at high risk for lung cancer.

OUTLINE: This is a randomized, multicenter study of lung cancer screening. Patients are randomized to one of two screening arms. Arm I: Patients undergo one spiral CT scan. Arm II: Patients undergo one chest x-ray. Patients and their primary care physicians are notified of test results within 3 weeks of the exam.

PROJECTED ACCRUAL: A total of 3,000 participants (1,500 per screening arm) will be accrued for this study at six screening centers (500 per center) by October 31, 2000.

DISEASE CHARACTERISTICS: See General Eligibility Criteria

PATIENT CHARACTERISTICS: Age: 55 to 74 Patients with a cigarette smoking history of at least 30 pack-years Current smoker OR Smoker who has quit smoking within the past 10 years No known prior history of lung cancer

PRIOR CONCURRENT THERAPY: No concurrent therapy for any cancer except nonmelanomatous skin cancer No prior removal of any portion of the lungs No concurrent participation in other cancer screening trial, including PLCO No concurrent participation in a primary cancer prevention trial other than a smoking cessation trial