Chest
Volume 132, Issue 3, Supplement, September 2007, Pages 69S-77S
Journal home page for Chest

DIAGNOSIS AND MANAGEMENT OF LUNG CANCER: ACCP GUIDELINES (2ND EDITION)
Screening for Lung Cancer: ACCP Evidence-Based Clinical Practice Guidelines (2nd Edition)

https://doi.org/10.1378/chest.07-1349Get rights and content

Background

Lung cancer typically exhibits symptoms only after the disease has spread, making cure unlikely. Because early-stage disease can be successfully treated, a screening technique that can detect lung cancer before it has spread might be useful in decreasing lung cancer mortality.

Objectives

In this article, we review the evidence for and against screening for lung cancer with low-dose CT and offer recommendations regarding its usefulness for asymptomatic patients with no history of cancer.

Results

Studies of lung cancer screening with chest radiograph and sputum cytology have failed to demonstrate that screening lowers lung cancer mortality rates. Published studies of newer screening technologies such as low-dose CT and “biomarker” screening report primarily on lung cancer detection rates and do not present sufficient data to determine whether the newer technologies will benefit or harm. Although researchers are conducting randomized trials of low-dose CT, results will not be available for several years. In the meantime, cost-effectiveness analyses and studies of nodule growth are considering practical questions but producing inconsistent findings.

Conclusions

For high-risk populations, no screening modality has been shown to alter mortality outcomes. We recommend that individuals undergo screening only when it is administered as a component of a well-designed clinical trial with appropriate human subjects' protections.

Section snippets

Materials and Methods

To update previous recommendations on lung cancer screening, we identified by a systematic review of the literature (see “Methodology for Lung Cancer Evidence Review and Guideline Development” chapter), the primary analysis of individuals who were screened for lung cancer between 2002 and May 2005, as well as studies that provided insights into the theoretical basis of screening or the clinical behavior of lung cancers found through screening. Supplemental material appropriate to this topic was

Results

Low-dose CT (LDCT) scanning remains the most promising of lung cancer screening techniques, but the results of ongoing randomized trials are not expected for at least another 2 to 3 years. In the meantime, researchers have pursued other approaches to evaluating the impact of CT screening on lung cancer outcomes and also focused on other issues that might affect how screening is used, such as investigating the hazard that smaller, early-stage, LDCT-detected nodules pose; the cost-effectiveness

Screening With LDCT

Using relatively low radiation exposure to create a low-resolution image of the entire thorax, LDCT screening is capable of detecting very small, early-stage cancers so that their shape and growth can be observed noninvasively. Previous research has demonstrated that compared with CXR, LDCT detects approximately three times as many small lung nodules; of those that are subsequently diagnosed as cancer, the overwhelming majority are stage I.4 For the additional early detection to benefit

Natural History of Clinically Apparent and CT-Detected Lung Cancers: Findings on Doubling Rates

Some research has explored use of the volume-doubling rate to predict the threat posed by smaller, screening-detected lung nodules, based on the hypothesis that nodules that are rapidly growing (ie, rapidly “doubling in size”) are more likely to cause significant disease. In other words, doubling times are examined on the basis of the assumption that the rate of doubling over a brief time period is at least crudely reflective of a tumor's past behavior and can be used as a proxy for the future

Cost-effectiveness of LDCT

Researchers have been eager to determine the cost-effectiveness of lung cancer screening, a task made difficult by the absence of efficacy data (Table 2).15, 17, 18, 41 Two studies have examined the cost of a single, “prevalence” screening compared with no screening on the basis of the apparent shift in stage distribution reported in the Early Lung Cancer Action Project (ELCAP) cohort (85% stage I in screening arm vs 21% stage I in the no-screening arm).15, 16 Both estimated the incremental

LDCT Ongoing and Future Studies

At least two randomized trials of LDCT are under way. The National Lung Screening Trial has randomly assigned 50,000 high-risk smokers, between 55 and 74 years of age, to annual screening with LDCT or CXR at 36 sites in the United States (http://www.cancer.gov/nlst/screeningcenters). The study is designed to have a 90% power to detect a mortality reduction of 20% by 2009. The NELSON trial,21 a collaboration between the Netherlands and Belgium, has randomly assigned 16,000 smokers to LDCT

Available Estimates of the Impact of LDCT Screening on Lung Cancer Mortality and Survival

Although there are not yet comparative data on the rate of lung cancer mortality among patients who are screened with LDCT compared with what might have happened had individuals not been screened, some preliminary analyses are pessimistic. In a study of 1,520 smokers and former smokers who received 5 years of annual LDCT scans at the Mayo Clinic, Swensen et al22 found that lung cancer incidence and mortality rates were comparable to those in the Mayo Lung Project, after adjusting subsets by age

LDCT

At present, the risks of LDCT are readily observable, but the impact on mortality remains unknown. Even if LDCT is ultimately shown to effect a mortality reduction, the legitimate concern about overdiagnosing cancers, the uncertainty about how to assess nodule growth rates, the influence of patient risk level on effectiveness and cost-effectiveness, and the high rates of benign nodule detection and subsequent treatment prompted by such detection all suggest that the cumulative consequences of

REFERENCES (41)

  • PetricoinEF et al.

    Clinical applications of proteomics

    J Nutr

    (2003)
  • PetricoinEF et al.

    Proteomic approaches in cancer risk and response assessment

    Trends Mol Med

    (2004)
  • ChirikosTN et al.

    Screening for lung cancer with CT: a preliminary cost-effectiveness analysis

    Chest

    (2002)
  • American Cancer Society. (2007)Cancer facts and figures 2007 American Cancer Society. Atlanta,...
  • BlackC et al.

    The clinical effectiveness and cost-effectiveness of computed tomography screening for lung cancer: systematic reviews

    Health Technol Assess

    (2006)
  • MarcusPM et al.

    Lung cancer mortality in the Mayo Lung Project: impact of extended follow-up

    J Natl Cancer Inst

    (2000)
  • KubikAK et al.

    Czech Study on Lung Cancer Screening: post-trial follow-up of lung cancer deaths up to year 15 since enrollment

    Cancer

    (2000)
  • DollR et al.

    Mortality in relation to smoking: 50 years' observations on male British doctors

    BMJ

    (2004)
  • GodtfredsenNS et al.

    Effect of smoking reduction on lung cancer risk

    JAMA

    (2005)
  • PetoR et al.

    Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies

    BMJ

    (2000)
  • Cited by (0)

    The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).

    View full text