Benefits and harms of computed tomography lung cancer screening strategies: a comparative modeling study for the U.S. Preventive Services Task Force.
BACKGROUND: The optimum screening policy for lung cancer is unknown.
OBJECTIVE: To identify efficient computed tomography (CT) screening scenarios in which relatively more lung cancer deaths are averted for fewer CT screening examinations.
DESIGN: Comparative modeling study using 5 independent models.
DATA SOURCES: The National Lung Screening Trial; the Prostate, Lung, Colorectal, and Ovarian Cancer Screening trial; the Surveillance, Epidemiology, and End Results program; and the U.S. Smoking History Generator.
TARGET POPULATION: U.S. cohort born in 1950.
TIME HORIZON: Cohort followed from ages 45 to 90 years.
INTERVENTION: 576 scenarios with varying eligibility criteria (age, pack-years of smoking, years since quitting) and screening intervals.
OUTCOME MEASURES: Benefits included lung cancer deaths averted or life-years gained. Harms included CT examinations, false-positive results (including those obtained from biopsy/surgery), overdiagnosed cases, and radiation-related deaths.
RESULTS OF BEST-CASE SCENARIO: The most advantageous strategy was annual screening from ages 55 through 80 years for ever-smokers with a smoking history of at least 30 pack-years and ex-smokers with less than 15 years since quitting. It would lead to 50% (model ranges, 45% to 54%) of cases of cancer being detected at an early stage (stage I/II), 575 screening examinations per lung cancer death averted, a 14% (range, 8.2% to 23.5%) reduction in lung cancer mortality, 497 lung cancer deaths averted, and 5250 life-years gained per the 100,000-member cohort. Harms would include 67,550 false-positive test results, 910 biopsies or surgeries for benign lesions, and 190 overdiagnosed cases of cancer (3.7% of all cases of lung cancer [model ranges, 1.4% to 8.3%]).
RESULTS OF SENSITIVITY ANALYSIS: The number of cancer deaths averted for the scenario varied across models between 177 and 862; the number of overdiagnosed cases of cancer varied between 72 and 426.
LIMITATIONS: Scenarios assumed 100% screening adherence. Data derived from trials with short duration were extrapolated to lifetime follow-up.
CONCLUSION: Annual CT screening for lung cancer has a favorable benefit-harm ratio for individuals aged 55 through 80 years with 30 or more pack-years' exposure to smoking.
PRIMARY FUNDING SOURCE: National Cancer Institute.