CXR

LDCT

Sputum cytology

• To update health care professionals and the public on issues regarding testing for early lung cancer detection in light of emerging data on new imaging technologies

• To provide updated, evidence-based, clinically relevant guidelines for the early detection of lung cancer

• To update the 1994 recommendations of the Canadian Task Force of Preventive Health care for lung cancer screening
• To make recommendations on the effectiveness of chest radiographic examination and spiral computed tomography (CT) for lung cancer screening in asymptomatic patients

• To summarize the current U.S. Preventive Services Task Force (USPSTF) recommendation on screening for lung cancer and the supporting scientific evidence
• To update the 1996 recommendations contained in the Guide to Clinical Preventive Services, second edition

• United States
• Individuals at risk for the development of lung cancer, including current and/or former smokers

• United States
• Individuals at risk for lung cancer but without symptoms or a history of cancer

• Canada
• Asymptomatic adults with a history of smoking with no previous history of lung cancer

• United States
• Asymptomatic persons seen in primary care settings

Advanced Practice Nurses; Allied Health Personnel; Health Care Providers; Health Plans; Hospitals; Managed Care Organizations; Nurses; Patients; Physician Assistants; Physicians; Public Health Departments

Advanced Practice Nurses; Allied Health Personnel; Health Care Providers; Nurses; Patients; Physicians; Psychologists/Non-physician Behavioral Health Clinicians; Social Workers

Advanced Practice Nurses; Allied Health Personnel; Physician Assistants; Physicians

Advanced Practice Nurses; Allied Health Personnel; Nurses; Physician Assistants; Physicians

• The ACS does not recommend lung cancer screening for asymptomatic individuals at risk for lung cancer.
• However, individual physicians and patients may decide that the evidence is sufficient to warrant the use of screening tests on an individual basis.
• The ACS recommends that, to the extent possible, individuals at risk for lung cancer due to current or prior smoking history, history of significant exposure to second-hand smoke, or occupational history be aware of their continuing lung cancer risk. Those who seek testing for early lung cancer detection should be informed about what is currently known about the benefits, limitations, and risks associated with conventional and emerging early detection technologies, as well as the associated diagnostic procedures and treatment.
• Current technologies for detecting early lung cancer include imaging modalities (CXR, LDCT) and cytological and molecular evaluations of lung sputum.
• Results from screening studies using spiral CT have been regarded as sufficiently encouraging to lead a growing number of institutions and facilities to promote CT screening to asymptomatic individuals at risk for lung cancer, with such promotion likely to increase. Since both media reports and local advertising may stimulate interest in spiral CT testing among health care providers and individuals at higher risk, the ACS has determined that updated guidance about early lung cancer detection is appropriate.
• Given the high rate of positive results that occur with CT screening for lung cancer and the complexity of the algorithm for working up small nodules, there is reason to be concerned about broad dissemination of lung screening outside of experienced, multi-specialty settings and prior to validation of this new technology. For this reason, it is critically important during this period of evolving investigations into the efficacy of spiral CT and other modalities that appropriate and influential professional organizations provide a foundation for best practices based upon the current state-of-the art, and also promote informed decision-making for patients about possible benefits, risks, and limitations of testing for early lung cancer detection. Individuals interested in early detection also should be encouraged to participate in trials.

• We do not recommend that low-dose helical CT be used to screen for lung cancer except in the context of a well-designed clinical trial. Grade of recommendation, 2C
• We recommend against the use of serial CXR to screen for the presence of lung cancer. Grade of recommendation, 1A
• We recommend against the use of single or serial sputum cytologic evaluation to screen for the presence of lung cancer. Grade of recommendation, 1A

Chest X-ray

The CTFPHC concludes that there is fair evidence to recommend against screening asymptomatic people for lung cancer using chest radiographic examination. (D recommendation) (Manser et al., 2002 [I, fair]; Kubik, Parkin, & Zatloukal, 2000 [I, fair]; Marcus et al., 2000 [I, fair]; Nishii et al., 2001 [II-2, fair]; Okamoto et al., 1999 [II-2, fair]; Sagawa et al., 2001 [II-2, fair]; Sobue, 2000 [II-2, fair]; Tsukada et al., 2001 [II-2, fair]).

Low Dose Computed Tomography

The CTFPHC concludes that there is insufficient evidence (in quantity and/or quality) to make a recommendation as to whether spiral CT scanning should be used for screening asymptomatic people for lung cancer. However, other factors may influence decision-making. (I recommendation). (Henschke et al., 1999; Henschke et al., 2001; Sone et al., 1998; Sone et al., 2001; Diederich et al., 2000 [II-2, III]).

The USPSTF concludes that the evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer with either LDCT, CXR, sputum cytology, or a combination of these tests. I recommendation

Clinical Considerations

• The benefit of screening for lung cancer has not been established in any group, including asymptomatic high-risk populations such as older smokers. The balance of harms and benefits becomes increasingly unfavorable for persons at lower risk, such as nonsmokers.
• The sensitivity of LDCT for detecting lung cancer is 4 times greater than the sensitivity of CXR. However, LDCT is also associated with a greater number of false-positive results, more radiation exposure, and increased costs compared with CXR.
• Because of the high rate of false-positive results, many patients will undergo invasive diagnostic procedures as a result of lung cancer screening. Although the morbidity and mortality rates from these procedures in asymptomatic individuals are not available, mortality rates because of complications from surgical interventions in symptomatic patients reportedly range from 1.3 to 11.6%; morbidity rates range from 8.8 to 44%, with higher rates associated with larger resections.
• Other potential harms of screening are potential anxiety and concern as a result of false-positive tests, as well as possible false reassurance because of false-negative results. However, these harms have not been adequately studied.

Reduced mortality associated with lung cancer.

Appropriate screening of patients at risk for lung cancer

Appropriate use of lung cancer screening in asymptomatic people may result in the following:

• Decreased number of false-positives associated with screening tests
• Decreased risk of invasive diagnostic procedures to confirm suspicious or false-positive findings
• Prevention of exposure of the patient to unnecessary radiation
• Prevention of decreased motivation to stop smoking if a false-negative result is obtained

Additional potential benefits of specific screening procedures:

Spiral CT scanning provides the hope of a more sensitive screening test than CXR, and prospective studies have demonstrated an improved detection of smaller lesions. However, it is unclear whether improved detection will lead to improved mortality.

The USPSTF found fair evidence that screening with LDCT, CXR, or sputum cytology can detect lung cancer at an earlier stage than lung cancer would be detected in an unscreened population; however, the USPSTF found poor evidence that any screening strategy for lung cancer decreases mortality.

Not stated

Not stated

Potential Harms of Not Screening

May miss detection of early stage lung cancer

Potential Harms of Screening

In one reported study, 50% of positive CXRs were not suspicious for cancer on spiral CT and, from RCTs, even suspicious CXRs are often false positives after diagnostic workup (positive predictive values ranging from 41%-60%). Nevertheless, spiral CT picks up many more lesions, and 90-92% of "positive" CT scans turn out not to be cancerous. These patients are exposed not only to radiation, but also to the anxiety and risks involved in having a suspicious finding confirmed by invasive diagnostic procedures. The biopsy rate for spiral CT ranges from 11-12%, 24-26% of which prove to be non-cancerous. Another study reported that 18 CT scans were either falsely read as negative or did not pick up a cancer detected by sputum cytology, leading to a false negative rate of 45% of spiral CT.

False negatives carry with them a false reassurance and a risk that the patient will be less motivated to quit smoking.

• Because of the invasive nature of diagnostic testing and the possibility of a high number of false-positive tests in certain populations, there is potential for significant harms from screening. Therefore, the USPSTF could not determine the balance between the benefits and harms of screening for lung cancer.
• Other potential harms of screening are potential anxiety and concern as a result of false-positive tests, as well as possible false reassurance because of false-negative results. However, these harms have not been adequately studied.

Quality of Evidence Scale

High (A) Randomized controlled trials (RCTs) without important limitations or overwhelming evidence from observational studies

Moderate (B) RCTs with important limitations (inconsistent results, methodologic flaws, indirect, or imprecise) or exceptionally strong evidence from observational studies

Low or very low (C) Observational studies or case series

Strength of Recommendations

1A - Strong recommendation

1B - Strong recommendation

1C - Strong recommendation

2A - Weak recommendation

2B - Weak recommendation

2C - Weak recommendation

Levels of Evidence - Research Design Rating

I: Evidence from randomized controlled trials (RCT)

II-1: Evidence from controlled trials without randomization

II-2: Evidence from cohort or case-control analytic studies, preferably from more than 1 centre or research group

II-3: Evidence from comparisons between times or places with or without the intervention; dramatic results in uncontrolled experiments could also be included here

III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

Quality (Internal Validity) Rating

Good: A study that meets all design-specific criteria* well

Fair: A study that does not meet (or it is not clear that it meets) at least one design-specific criterion* but has no known "fatal flaw"

Poor: A study that has at least one design-specific* "fatal flaw," or an accumulation of lesser flaws to the extent that the results of the study are not deemed able to inform recommendations

*General design-specific criteria are outlined in Harris RP, Helfand M, Woolf SH, Lohr KN, Mulrow CD, Teutsch SM, Atkins D. Current Methods of the U.S. Preventive Services Task Force: A Review of the Process. Am J Prev Med 2001;20(suppl 3):21-35.

Recommendations Grades for Specific Clinical Preventive Actions

A: The Canadian Task Force (CTF) concludes that there is good evidence to recommend the clinical preventive action.

B: The CTF concludes that there is fair evidence to recommend the clinical preventive action.

C: The CTF concludes that the existing evidence is conflicting and does not allow making a recommendation for or against use of the clinical preventive action; however, other factors may influence decision-making.

D: The CTF concludes that there is fair evidence to recommend against the clinical preventive action.

E: The CTF concludes that there is good evidence to recommend against the clinical preventive action.

I: The CTF concludes that there is insufficient evidence (in quantity and/or quality) to make a recommendation; however, other factors may influence decision-making.

References

• Diederich S, Wormanns D, Lenzen H, Semik M, Thomas M, Peters PE. Screening for asymptomatic early bronchogenic carcinoma with low dose CT of the chest. Cancer 2000 Dec 1;89(11 Suppl):2483-4. PubMed
• Henschke CI, McCauley DI, Yankelevitz DF, Naidich DP, McGuinness G, Miettinen OS, Libby DM, Pasmantier MW, Koizumi J, Altorki NK, Smith JP. Early lung cancer action project: overall design and findings from baseline screening. Lancet 1999 Jul 10;354(9173):99-105. PubMed
• Henschke CI, Naidich DP, Yankelevitz DF, McGuinness G, McCauley DI, Smith JP, Libby D, Pasmantier M, Vazquez M, Koizumi J, Flieder D, Altorki N, Miettinen OS. Early lung cancer action project: initial findings on repeat screenings. Cancer 2001 Jul 1;92(1):153-9. PubMed
• Kubik AK, Parkin DM, Zatloukal P. Czech Study on Lung Cancer Screening: post-trial follow-up of lung cancer deaths up to year 15 since enrollment. Cancer 2000 Dec 1;89(11 Suppl):2363-8. PubMed
• Manser RL, Irving LB, Stone C, Byrnes G, Abramson M, Campbell D. Screening for lung cancer (Cochrane Review). In: The Cochrane Library [database online]. Issue 4. Oxford: Update Software; 2002
• Marcus PM, Bergstralh EJ, Fagerstrom RM, Williams DE, Fontana R, Taylor WF, Prorok PC. Lung cancer mortality in the Mayo Lung Project: impact of extended follow-up. J Natl Cancer Inst 2000 Aug 16;92(16):1308-16. PubMed
• Nishii K, Ueoka H, Kiura K, Kodani T, Tabata M, Shibayama T, Gemba K, Kitajima T, Hiraki A, Kawaraya M, Nakayama T, Harada M. A case-control study of lung cancer screening in Okayama Prefecture, Japan. Lung Cancer 2001 Dec;34(3):325-32. PubMed
• Okamoto N, Suzuki T, Hasegawa H, Gotoh T, Hagiwara S, Sekimoto M, Kaneko M. Evaluation of a clinic-based screening program for lung cancer with a case-control design in Kanagawa, Japan. Lung Cancer 1999 Aug;25(2):77-85. PubMed
• Sagawa M, Tsubono Y, Saito Y, Sato M, Tsuji I, Takahashi S, Usuda K, Tanita T, Kondo T, Fujimura S. A case-control study for evaluating the efficacy of mass screening program for lung cancer in Miyagi Prefecture, Japan. Cancer 2001 Aug 1;92(3):588-94. PubMed
• Sobue T. A case-control study for evaluating lung cancer screening in Japan. Cancer 2000 Dec 1;89(11 Suppl):2392-6. PubMed
• Sone S, Li F, Yang ZG, Honda T, Maruyama Y, Takashima S, Hasegawa M, Kawakami S, Kubo K, Haniuda M, Yamanda T. Results of three-year mass screening programme for lung cancer using mobile low-dose spiral computed tomography scanner. Br J Cancer 2001 Jan 5;84(1):25-32. PubMed
• Sone S, Takashima S, Li F, Yang Z, Honda T, Maruyama Y, Hasegawa M, Yamanda T, Kubo K, Hanamura K, Asakura K. Mass screening for lung cancer with mobile spiral computed tomography scanner. Lancet 1998 Apr 25;351(9111):1242-5. PubMed
• Tsukada H, Kurita Y, Yokoyama A, Wakai S, Nakayama T, Sagawa M, Misawa H. An evaluation of screening for lung cancer in Niigata Prefecture, Japan: a population-based case-control study. Br J Cancer 2001 Nov 2;85(9):1326-31. PubMed

The USPSTF grades the quality of the overall evidence for a service on a 3-point scale (good, fair, poor):

Good

Evidence includes consistent results from well-designed, well-conducted studies in representative populations that directly assess effects on health outcomes.

Fair

Evidence is sufficient to determine effects on health outcomes, but the strength of the evidence is limited by the number, quality, or consistency of the individual studies, generalizability to routine practice, or indirect nature of the evidence on health outcomes.

Poor

Evidence is insufficient to assess the effects on health outcomes because of limited number or power of studies, important flaws in their design or conduct, gaps in the chain of evidence, or lack of information on important health outcomes.

The USPSTF grades its recommendations according to one of 5 classifications (A, B, C, D, I) reflecting the strength of evidence and magnitude of net benefit (benefits minus harms):

A

The USPSTF strongly recommends that clinicians provide [the service] to eligible patients. The USPSTF found good evidence that [the service] improves important health outcomes and concludes that benefits substantially outweigh harms.

B

The USPSTF recommends that clinicians provide [the service] to eligible patients. The USPSTF found at least fair evidence that [the service] improves important health outcomes and concludes that benefits outweigh harms.

C

The USPSTF makes no recommendation for or against routine provision of [the service]. The USPSTF found at least fair evidence that [the service] can improve health outcomes but concludes that the balance of benefits and harms is too close to justify a general recommendation.

D

The USPSTF recommends against routinely providing [the service] to asymptomatic patients. The USPSTF found at least fair evidence that [the service] is ineffective or that harms outweigh benefits.

I

The USPSTF concludes that the evidence is insufficient to recommend for or against routinely providing [the service]. Evidence that [the service] is effective is lacking, of poor quality, or conflicting and the balance of benefits and harms cannot be determined.