BACKGROUND: Low-dose computed tomography screening for lung cancer can reduce mortality among high-risk persons, but "false-positive" findings may result in unnecessary evaluations with attendant risks. The effect of alternative thresholds for defining a positive result on the rates of positive results and cancer diagnoses is unknown.
OBJECTIVE: To assess the frequency of positive results and potential delays in diagnosis in the baseline round of screening by using more restrictive thresholds.
DESIGN: Prospective cohort study.
SETTING: Multi-institutional International Early Lung Cancer Action Program.
PATIENTS: 21 136 participants with baseline computed tomography performed between 2006 and 2010.
MEASUREMENTS: The frequency of solid and part-solid pulmonary nodules and the rate of lung cancer diagnosis by using current (5 mm) and more restrictive thresholds of nodule diameter.
RESULTS: The frequency of positive results in the baseline round by using the current definition of positive result (any parenchymal, solid or part-solid, noncalcified nodule ≥5.0 mm) was 16% (3396/21 136). When alternative threshold values of 6.0, 7.0, 8.0 and 9.0 mm were used, the frequencies of positive results were 10.2% (95% CI, 9.8% to 10.6%), 7.1% (CI, 6.7% to 7.4%), 5.1% (CI, 4.8% to 5.4%), and 4.0% (CI, 3.7% to 4.2%), respectively. Use of these alternative definitions would have reduced the work-up by 36%, 56%, 68%, and 75%, respectively. Concomitantly, lung cancer diagnostics would have been delayed by at most 9 months for 0%, 5.0% (CI, 1.1% to 9.0%), 5.9% (CI, 1.7 to 10.1%), and 6.7% (CI, 2.2% to 11.2%) of the cases of cancer, respectively.
LIMITATION: This was a retrospective analysis and thus whether delays in diagnosis would have altered outcomes cannot be determined.
CONCLUSION: These findings suggest that using a threshold of 7 or 8 mm to define positive results in the baseline round of computed tomography screening for lung cancer should be prospectively evaluated to determine whether the benefits of decreasing further work-up outweigh the consequent delay in diagnosis in some patients.
|Number of pages||7|
|Journal||Annals of Internal Medicine|
|State||Published - 19 Feb 2013|
- Delayed Diagnosis
- Lung Neoplasms/diagnostic imaging
- Mass Screening/methods
- Radiation Dosage
- Retrospective Studies
- Tomography, X-Ray Computed/methods