Chest X-ray Screening for Lung Cancer Risk Reduction in Adults Aged 55-74

PRIMARY OBJECTIVES: I. To determine whether screening with chest x-ray can reduce mortality from lung cancer in women and men aged 55-74 at entry. SECONDARY OBJECTIVES: I. To assess screening variables, other than mortality, for each of the interventions including sensitivity, specificity, and positive predictive value. II. To assess the incidence, stage, and survival of cancer cases. III. To investigate the mortality predictive value of biologic and/or prognostic characterizations of tumor tissue as intermediate endpoints. IV. To conduct biomolecular and genetic research into factors associated with cancer carcinogenesis and promotion, as well as the early detection of these factors. OUTLINE: Participants in the overall PLCO study are stratified by screening center, gender, and age (55-59 vs 60-64 vs 65-69 vs 70-74). Participants are randomized to 1 of 2 arms (control vs screening). ARM I (Control): Participants receive standard medical care. Participants complete a Diet History Questionnaire (DHQ) at baseline. ARM II (Lung Screening): Participants undergo a chest x-ray (one postero-anterior view) at baseline and annually for 2 years. Participants classified as "smokers" undergo an additional chest x-ray at year 3. A scheduling and tracking procedure is implemented to ensure regular attendance at repeat screens for participants screened negative or for those who are designated suspicious or positive at screening but for whom subsequent diagnostic procedures do not reveal lung cancer (follow-up diagnostic procedures are through their own medical care environment). Participants diagnosed with lung cancer via a screening test are referred for treatment in accordance with current accepted practice for appropriate stage of disease, patient age, and medical condition; a procedure is provided for contact with qualified medical personnel to insure appropriate therapy. Participants complete a Baseline Questionnaire (BQF/M) to assess smoking status. Participants complete a Dietary Questionnaire (DQX) at baseline and DHQ at year 3. An Annual Study Update (ADU) (previously referred to as the Periodic Survey of Health \[PSH\] questionnaire) is mailed to each participant annually for 13 years to identify all prevalent and incident lung cancers as all deaths that occur among both screened and control subjects during the trial. After completion of screening, participants are followed up for at least 13 years.