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Background: Direct-to-consumer promotion of lung cancer screening has increased, especially low-dose computed tomography (CT). However, screening exposes healthy persons to potential harms, and cumulative false-positive rates for low-dose CT have never been formally reported.Objective: To quantify the cumulative risk that a person who participated in a 1- or 2-year lung cancer screening examination would receive at least 1 false-positive result, as well as rates of unnecessary diagnostic procedures.Design: Randomized, controlled trial of low-dose CT versus chest radiography. (ClinicalTrials.gov registration number: NCT00006382)Setting: Feasibility study for the ongoing National Lung Screening Trial.Patients: Current or former smokers, aged 55 to 74 years, with a smoking history of 30 pack-years or more and no history of lung cancer (n = 3190).Intervention: Random assignment to low-dose CT or chest radiography with baseline and 1 repeated annual screening; 1-year follow-up after the final screening. Randomization was centralized and stratified by age, sex, and study center.Measurements: False-positive screenings, defined as a positive screening with a completed negative work-up or 12 months or more of follow-up with no lung cancer diagnosis.Results: By using a Kaplan-Meier analysis, a person's cumulative probability of 1 or more false-positive low-dose CT examinations was 21% (95% CI, 19% to 23%) after 1 screening and 33% (CI, 31% to 35%) after 2. The rates for chest radiography were 9% (CI, 8% to 11%) and 15% (CI, 13% to 16%), respectively. A total of 7% of participants with a false-positive low-dose CT examination and 4% with a false-positive chest radiography had a resulting invasive procedure.Limitations: Screening was limited to 2 rounds. Follow-up after the second screening was limited to 12 months. The false-negative rate is probably an underestimate.Conclusion: Risks for false-positive results on lung cancer screening tests are substantial after only 2 annual examinations, particularly for low-dose CT. Further study of resulting economic, psychosocial, and physical burdens of these methods is warranted.Primary Funding Source: National Cancer Institute. [ABSTRACT FROM AUTHOR]

Background: Lack of confidence in postpolypectomy surveillance guidelines may be a factor in the observed low adherence rates among providers., Objective: To assess the 2006 postpolypectomy colonoscopy surveillance guidelines, which recommend 3-year follow-up colonoscopy for individuals with high-risk adenomas (defined as > or =3 adenomas or any advanced adenomas) and 5- to 10-year follow-up for patients with 2 or fewer nonadvanced adenomas, who are considered to be at low risk., Design: Analysis of prospective data from the Polyp Prevention Trial., Setting: United States., Participants: 1905 patients who had colorectal adenomas removed at baseline screening or diagnostic colonoscopy and completed the trial., Measurements: Baseline adenoma characteristics, risk-stratified according to definitions used in the guidelines, were examined as predictors for advanced adenoma recurrence., Results: 125 patients (6.6%) had advanced and 629 (33.0%) had nonadvanced adenoma recurrence; 1151 (60.4%) had no recurrence within 4 years of follow-up. The probability of advanced adenoma recurrence was 0.09 (95% CI, 0.07 to 0.11) among patients with high-risk adenomas at baseline and 0.05 (CI, 0.04 to 0.06) among those with low-risk adenomas at baseline. The relative risk for advanced adenoma recurrence for patients with high-risk adenomas versus those with low-risk adenomas at baseline was 1.68 (CI, 1.19 to 2.38) when advanced adenoma recurrence was compared with no advanced adenoma recurrence and 1.76 (CI, 1.26 to 2.46) when advanced adenoma recurrence was compared with no adenoma recurrence. The c-statistics for these 2 comparisons were 0.68 and 0.72, respectively., Limitation: Participants were self-selected and had restrictions on the degree of obesity., Conclusion: Although the risk for recurrence of advanced adenoma within 4 years is greater for patients with high-risk adenomas at baseline than for those with low-risk adenomas, the discrimination of this risk stratification scheme is relatively low.