Lung Cancer Screening (PDQ®): Screening - Health Professional Information [NCI]

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Lung Cancer Screening (PDQ®): Screening - Health Professional Information [NCI]

This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at or call 1-800-4-CANCER.

Lung Cancer Screening

Summary of Evidence

Separate PDQ summaries on Lung Cancer Prevention, Small Cell Lung Cancer Treatment, Non-Small Cell Lung Cancer Treatment, and Levels of Evidence for Cancer Screening and Prevention Studies are also available.

Screening for Lung Cancer With Chest X-Ray and/or Sputum Cytology


Based on fair evidence, screening does not reduce mortality from lung cancer.

Description of the Evidence

  • Study Design: Evidence obtained from randomized controlled trials.
  • Internal Validity: Fair, due to lack of unscreened groups and contamination.
  • Consistency: Good.
  • Direction and Magnitude of Effect: No evidence of effect.
  • External Validity: Fair, due to lack of women and minority groups.


Based on solid evidence, screening would lead to false-positive tests and unnecessary invasive diagnostic procedures and treatments.

Description of the Evidence

  • Study Design: Evidence obtained from randomized controlled trials.
  • Internal Validity: Fair.
  • Consistency: Good.
  • Direction and Magnitude of Effect: False-positive results range from 4% to 15%; there is a possibility of overdiagnosis and overtreatment (magnitude uncertain).
  • External Validity: Fair.

Screening for Lung Cancer With Low-Dose Helical Computed Tomography (LDCT)


The evidence is inadequate to determine whether screening reduces mortality from lung cancer.

Description of the Evidence

  • Study Design: Evidence obtained from cohort or case-control studies.
  • Internal Validity: Poor for answering the question of mortality reduction from screening with LDCT.
  • Consistency: Good.
  • Direction and Magnitude of Effect: Cannot determine from the available studies.
  • External Validity: Not applicable; the internal validity of the evidence is poor.


Based on solid evidence, screening would lead to false-positive tests and unnecessary invasive diagnostic procedures and treatments.

Description of the Evidence

  • Study Design: Evidence obtained from cohort or case-control studies.
  • Internal Validity: Poor.
  • Consistency: Good.
  • Direction and Magnitude of Effect: False-positive results range from 20% to 50%; overdiagnosis and overtreatment are possible (magnitude uncertain).
  • External Validity: Fair.


Incidence and Mortality

Lung cancer is the most commonly occurring noncutaneous cancer in men and women combined in the United States and is the leading cause of cancer deaths. In 2011 alone, it is estimated that there will be 221,130 new cases diagnosed, and 71,340 women and 85,600 men will die due to this disease. The lung cancer death rate rose rapidly over several decades in both sexes, with a persistent decline for males commencing in 1991. Death rates in men have been decreasing by 3% per year since 2005. Lung cancer death rates in women have been decreasing by 0.9% per year since 2003.[1]

Tobacco Use and Secondhand Smoke

The most important risk factor for lung cancer (and for many other cancers) is tobacco use.[2,3] Cigarette smoking has been definitively established by epidemiologic and preclinical animal experimental data as the primary cause of lung cancer. This causative link has been widely recognized since the 1960s, when national reports in Great Britain and the United States brought the cancer risk of smoking prominently to the public's attention.[3] The percentages of lung cancers estimated to be caused by tobacco smoking in males and females are 90% and 78%, respectively.

Environmental or secondhand tobacco smoke is also implicated in causing lung cancer.[4] Environmental tobacco smoke has the same components as inhaled mainstream smoke, although in lower absolute concentrations; between 1% and 10% depending on the constituent. Carcinogenic compounds in tobacco smoke include the polynuclear aromatic hydrocarbons (PAHs), including the classical carcinogen benzo[a]pyrene and the nicotine-derived tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In rodents, total doses of both PAH and NNK that are similar to doses received by humans in a lifetime of smoking induce pulmonary tumors.[5] Elevated biomarkers of tobacco exposure, including urinary cotinine, tobacco-related carcinogen metabolites, and carcinogen-protein adducts, are seen in passive or secondhand smokers.[6,7,8,9,10]

Lung cancer is considered to be the end stage of multistep carcinogenesis. Suggestive evidence of genetic damage is the association of cigarette smoking with the formation of the DNA adducts in human lung tissue. An unequivocal link between tobacco smoke and lung carcinogenesis has been established by molecular data.[11,12]

Many other exposures have been established as causally associated with lung cancer, but even the combined effect of these additional factors is very small compared with cigarette smoking.[13] These additional causal factors are primarily related to occupational exposures to agents such as asbestos, arsenic, chromium, nickel, and radon.[13] Radon, a naturally occurring gas, is of relevance to the general public because of the potential exposure in homes.[13]


1. American Cancer Society.: Cancer Facts and Figures 2011. Atlanta, Ga: American Cancer Society, 2011. Also available online. Last accessed July 27, 2011.
2. U.S. Department of Health and Human Services.: The Health Consequences of Smoking: A Report of the Surgeon General. Atlanta, Ga: U.S. Department of Health and Human Services, CDC, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. Available online. Last accessed July 28, 2011.
3. Smoking and Health: Report of the Advisory Committee to the Surgeon General of the Public Health Service. Washington, DC: US Department of Health, Education, and Welfare, 1965. PHS Publ No 1103.
4. Hackshaw AK, Law MR, Wald NJ: The accumulated evidence on lung cancer and environmental tobacco smoke. BMJ 315 (7114): 980-8, 1997.
5. Cinciripini PM, Hecht SS, Henningfield JE, et al.: Tobacco addiction: implications for treatment and cancer prevention. J Natl Cancer Inst 89 (24): 1852-67, 1997.
6. Hecht SS, Carmella SG, Murphy SE, et al.: A tobacco-specific lung carcinogen in the urine of men exposed to cigarette smoke. N Engl J Med 329 (21): 1543-6, 1993.
7. Finette BA, O'Neill JP, Vacek PM, et al.: Gene mutations with characteristic deletions in cord blood T lymphocytes associated with passive maternal exposure to tobacco smoke. Nat Med 4 (10): 1144-51, 1998.
8. Parsons WD, Carmella SG, Akerkar S, et al.: A metabolite of the tobacco-specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in the urine of hospital workers exposed to environmental tobacco smoke. Cancer Epidemiol Biomarkers Prev 7 (3): 257-60, 1998.
9. Anderson KE, Carmella SG, Ye M, et al.: Metabolites of a tobacco-specific lung carcinogen in nonsmoking women exposed to environmental tobacco smoke. J Natl Cancer Inst 93 (5): 378-81, 2001.
10. Hecht SS: Human urinary carcinogen metabolites: biomarkers for investigating tobacco and cancer. Carcinogenesis 23 (6): 907-22, 2002.
11. Mao L, Lee JS, Kurie JM, et al.: Clonal genetic alterations in the lungs of current and former smokers. J Natl Cancer Inst 89 (12): 857-62, 1997.
12. Wistuba II, Lam S, Behrens C, et al.: Molecular damage in the bronchial epithelium of current and former smokers. J Natl Cancer Inst 89 (18): 1366-73, 1997.
13. Alberg AJ, Samet JM: Epidemiology of lung cancer. Chest 123 (1 Suppl): 21S-49S, 2003.

Evidence of Benefit

Chest X-Ray and Sputum Cytology

The most common screening tests for lung cancer are the chest x-ray and sputum cytology. Early studies evaluating these modalities include the following:

1. Philadelphia Pulmonary Neoplasm Research Project,[1] a nonrandomized, uncontrolled study that began in 1951.
2. Veterans Administration study,[2] a nonrandomized, uncontrolled study that was conducted from 1958 to 1961.
3. South London Lung Cancer Study,[3] a nonrandomized, uncontrolled study that was conducted from 1955 to 1963.
4. North London Cancer Study,[4,5] a randomized study that was conducted in the early 1960s and randomly assigned industrial firms to screening and no screening groups.
5. Kaiser Foundation Health Plan multiphasic screening trial,[6,7] a controlled trial that began in 1964 and included annual chest x-ray, spirometry, and medical questionnaire as part of the multiphasic screening.

None of these studies reported a statistically significant benefit of screening on lung cancer mortality. As an example, the South London study reported an increase in survival from the time of diagnosis of screen-detected lung cancer cases compared with other cases found in the same geographical region. There was, however, no adjustment for self-selection bias, lead-time bias, overdiagnosis bias, or length bias. Additionally, these studies were small, with a short follow-up period of typically less than 10 years, so that a small-to-moderate size or long-term effect was not demonstrable.

Other lung cancer screening investigations include a randomized trial in Czechoslovakia,[8] a nonrandomized but controlled trial in the former German Democratic Republic (GDR),[9] and case-control studies in the former GDR [10] and Japan.[11,12] The participants in the randomized arms of the Czechoslovakian study were screened with x-ray and cytology at two different frequencies, semiannual versus every 3 years. There was no unscreened control group. No difference in lung cancer mortality was observed; the relative risk (RR, screen group/control group) was 1.36 (95% confidence interval [CI], 0.94–1.98). The GDR nonrandomized study used semiannual chest fluoroscopy over a 6-year period in the intervention arm, while control patients were scheduled to undergo the same exam at 1-year to 2-year intervals. Allocation was based on district of residence. No reduction was observed in lung cancer mortality; the RR was 1.34 (95% CI, 0.94–1.98). Chest x-rays originally used for control of tuberculosis were evaluated in the German case-control study. The odds ratio (OR) showed no association between lung cancer death and having received a screening chest x-ray in both a general population-based control group (OR = 0.9; 95% CI, 0.5–1.5) and a hospital-based control group (OR = 1.1; 95% CI, 0.7–1.8).[10] X-ray histories among deceased lung cancer cases and matched controls were considered in a Japanese case-control study. In contrast to the German study, there was a suggestion of some screening benefit; the OR of dying from lung cancer for those screened within 12 months versus those not screened was 0.72 (95% CI, 0.50–1.03).[11] A meta-analysis of four other case-control studies conducted in Japan suggested mortality reductions of approximately 40%,[13] but potential for bias in these studies has been noted.[11]

Three other randomized trials have been conducted. The Mayo Lung Project (MLP) was initiated in 1971 and involved males aged 45 years or older who were heavy smokers.[14,15,16] Patients free of lung cancer on initial screening were randomly assigned to be offered screening with sputum cytology and chest x-ray every 4 months or to a group merely advised once at baseline to seek screening annually. At Johns Hopkins University [17,18,19,20] and Memorial Sloan-Kettering Cancer Center,[21,22] individuals were randomly assigned to intervention and control groups, which were both offered annual chest x-ray. In addition, the intervention group was offered sputum cytology every 4 months. None of the three trials reported a reduction in lung cancer mortality in the more intensively screened study group compared with the control group. Extension of follow-up to a median of 20.5 years in the MLP did not alter this conclusion.[23] The sustained excess of incident cases of lung cancer in the screened versus unscreened arms of the MLP during long-term follow-up, in the absence of evidence of a reduction in mortality, suggests that chest x-rays resulted in overdiagnosis of lung cancer.[24]

The Mayo trial is the most pertinent study for assessing annual x-ray screening because the use of screening x-rays differed in the two arms. There are several reservations about the Mayo study. The study was designed to detect a 50% reduction in lung cancer mortality and had insufficient power to demonstrate a lesser but medically important reduction of 10% to 15%. Also, about 50% of men in the control group received an annual chest x-ray,[16] so that contamination may have been sufficient to obscure an effect. Therapeutic advances may render early detection more effective today. Additionally, the spectrum of lung cancer type has shifted during the last two decades. Whereas the most common type used to be squamous cell cancer (usually centrally located), the most common type is now adenocarcinoma (usually peripherally located). The latter may be more amenable to early detection by chest x-ray. In contrast, sputum cytology is more sensitive in the detection of squamous cell cancer than in detecting adenocarcinoma.[25,26]

There is no good evidence that screening for lung cancer using chest x-ray or sputum cytology can reduce lung cancer mortality. Sputum cytology has not been shown to be effective when used as an adjunct to annual chest x-ray. Screening with chest x-ray plus sputum cytology appears to detect lung cancer at an earlier stage, but this would be expected in a screening test whether or not it was effective at reducing mortality. Similarly, case survival was improved relative to cases diagnosed through usual care, but this may simply reflect lead-time bias or overdiagnosis bias.[27] No reduction in lung cancer mortality has been observed.

Uncertainty in interpretation of results from completed studies has led to conflicting positions in the medical community and confusion in populations at risk regarding the value of chest x-ray screening. Only a properly designed randomized trial can demonstrate whether an important benefit exists. To this end, the National Cancer Institute (NCI) is conducting the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. This is a long-term randomized controlled trial in which 37,000 men are screened for prostate, lung, and colorectal cancers and 37,000 women are screened for lung, colorectal, and ovarian cancers. The lung component uses annual posteroanterior view chest x-ray as the screening modality. Equal numbers of men and women are followed up with routine medical care as controls.[28] In the baseline screen, 9% of participants had a positive screen, with significant increases in prevalence of positive screens with older age and more extensive smoking histories.[29] A total of 126 participants were subsequently diagnosed with lung cancer, and approximately one-half of these were stage I.[29]

Spiral Computed Tomography (CT)

There are intensive efforts to improve lung cancer screening with newer technologies, including low-dose helical computed tomography (LDCT) and molecular techniques.[30,31] LDCT is more sensitive than chest radiography. In the Early Lung Cancer Action Project (ELCAP) screening study,[31] LDCT detected almost six times as many stage I lung cancers as chest radiography, and most of these tumors were no larger than 1 cm in diameter. The effectiveness of screening with LDCT has not yet been evaluated in a controlled clinical trial.

Eight ongoing observational studies of LDCT in various parts of the world have been reported and summarized.[32] These are relatively small studies, ranging from about 600 to 8,000 participants, which began between 1992 and 2000. Most of the studies include a substantial percentage of females, and the studies in Japan include nonsmokers. Findings include a nodule or positivity rate of 5% to 51%, 0.4% to 3% lung cancers, 50% to 95% adenocarcinomas, 50% to 91% stage I or IA cancers, and estimates of sensitivity ranging from 40% to 95%.

Although the efficacy of CT screening in reducing lung cancer mortality is uncertain, CT screening has been hypothesized to have the benefit of promoting smoking cessation among current smokers. In a randomized controlled lung cancer CT screening trial in Denmark, all current smokers enrolled in the trial received a minimal smoking cessation intervention. After 1 year of follow-up, comparable quit rates were observed in the screened and unscreened groups (11.3% vs. 10.4%; P = .47).[33] Based on evidence from a well-designed randomized controlled trial, undergoing CT screening for lung cancer appears not to be significantly associated with smoking cessation.

Two harms must be considered against any potential benefit of screening with LDCT: false-positive test results and overdiagnosis. The false-positive test result, which is the more common and familiar harm, may lead to anxiety and invasive diagnostic procedures, such as percutaneous needle biopsy or thoracotomy. In the ELCAP study,[31] which used a CT slice thickness of 10 mm, noncalcified nodules were detected in 21% of patients without lung cancer at the prevalence screen. Thirty-one of 233 (13%) individuals with noncalcified nodules underwent biopsies, of which close to 90% (27/31) resulted in a diagnosis of malignancy, and the prevalence of cancers detected was 2.7%.

In a case series that defined the population at high risk of lung cancer by occupations associated with asbestos exposure, 58% accepted an invitation to participate in an LDCT screening program. The ELCAP screening protocol was applied in 1,119 asbestos-exposed people whose average age was 57 years. Twenty-five biopsies resulted in the detection of one stage IA and four late stage lung cancers. The authors concluded the screening program was not able to replicate the ELCAP results and was not cost effective for lung cancer screening in this population.[34]

A study in Ireland,[35] which aimed to reproduce the ELCAP study in high-risk but younger individuals, revealed a similar proportion of noncalcified nodules were detected using 10 mm CT slice thickness. In the Irish study (N = 449), however, the prevalence of cancers detected was substantially smaller (0.46%). Furthermore, several individuals underwent invasive procedures for ultimately benign conditions (three of four patients with nodules >10 mm who underwent biopsy had benign cytology; one had a thoracotomy that confirmed benign disease; three patients with mediastinal masses underwent biopsy and two had benign cysts). In two other studies, which used 5 mm CT slices, noncalcified nodules were detected in a much higher proportion of patients.[36,37]

In the Mayo Clinic study,[36] noncalcified nodules were detected in 51% of 1,520 patients at the prevalence screen and cumulatively in 74% after five subsequent annual screens.[38] Ninety-five percent of these nodules were less than 8 mm in diameter, for which the recommended follow-up was noncontrast CT in 3 to 6 months. However, eight patients had surgery for benign lesions, five of which appeared to grow on follow-up CT. In addition, screening with LDCT can detect abnormalities other than noncalcified nodules, including enlarged lymph nodes, abdominal aortic aneurysms, and renal and adrenal masses. During the first three rounds of screening in the Mayo clinic study, 696 such abnormalities were found in the 1,520 patients.

In a 2008 systematic review of chest CT lung cancer screening studies, the mean proportion of patients with any incidental abnormality was 65.2% (95% CI, 63.5%–66.9%). The mean proportion of patients with clinically significant incidental findings—defined as any abnormality considered to require additional diagnostic workup—was 14.2% (95% CI, 13.2%–15.2%).[39] It is not clear whether the detection of these abnormalities produces a net benefit or a net harm.[36]

A less familiar harm is overdiagnosis,[27] the diagnosis of a condition that would not have become clinically significant had it not been detected by screening. In the case of screening with LDCT, overdiagnosis could lead to unnecessary diagnosis of lung cancer requiring some combination of surgery (e.g., lobectomy, chemotherapy, and radiation therapy). Although overdiagnosis is almost impossible to document in a living individual, autopsy studies suggest that many individuals die with lung cancer rather than from it. In one study, about one-sixth of all lung cancers found at autopsy had not been clinically recognized before death.[40] Even this may be an underestimate because autopsy probably fails to detect many small lung cancers that are detectable by CT.[41] Studies in Japan provide additional evidence that screening with LDCT could lead to a substantial amount of overdiagnosis.[42] In a study in which smokers and nonsmokers were annually screened for lung cancer between 1996 and 1998 using LDCT, the overall rate of screen-detected lung cancers was very similar in the two groups: 0.46% for smokers (mainly men) and 0.41% for nonsmokers (mainly women).[43] The nonsmoking group may have included individuals who were at an elevated risk for lung cancers for other reasons, but no information is provided on this point. A second study involving both smokers and nonsmokers reported a similar finding of a 1.1% lung cancer detection rate in both groups.[44] Confirmative studies are needed to establish the level of overdiagnosis that might be associated with CT screening for lung cancer. In that same population, the volume-doubling times of 61 lung cancers were estimated using an exponential model and successive CT images. Lesions were classified into three types: (1) type G (ground glass opacity), (2) type GS (focal glass opacity with a solid central component), and (3) type S (solid nodule). The mean-doubling times were 813 days, 457 days, and 149 days for types G, GS, and S, respectively. In this study, annual CT screening identified a large number of slowly growing adenocarcinomas that were not visible on chest x-ray.[45] Before spiral CT is accepted into medical practice, it is critical to determine whether this modality does more good than harm in a randomized controlled trial with lung cancer mortality as the endpoint.[46,47]

To assess the feasibility of conducting a randomized controlled trial in asymptomatic individuals at high risk of lung cancer, the NCI conducted the Lung Screening Study (LSS). Between September 5, 2000 and November 15, 2000, six PLCO contract screening centers recruited 3,318 heavy or long-term smokers (inclusion required a 30 pack-year smoking history) who were not participants in the PLCO trial and randomly assigned them to receive a baseline and 1-year LDCT (1,660) or chest x-ray (1,658). The two study arms were essentially identical on age, sex, and history of smoking. Compliance with screening declined from 96% at baseline to 86% at 1 year in the LDCT arm and from 93% at baseline to 80% at 1 year in the chest x-ray arm. In a survey of all study patients who had greater than a 98% response rate, 2.6% of chest x-ray patients reported having a CT exam outside the trial between annual screens, and 13% of LDCT patients had outside chest x-rays. Positivity rates in the LDCT arm were 20.5% at baseline exam and 25.8% at the 1-year screen; the chest x-ray arm, positivity rates were 9.8% and 8.7%, respectively. Positivity rates were higher among current smokers and older patients. Lung cancer was diagnosed in 1.9% of participants in the LDCT arm at baseline and 0.57% at year 1; in the chest x-ray arm, lung cancer was diagnosed in 0.45% and 0.68% of participants, respectively. The cumulative probability that a participant would receive at least one false-positive test during the study was 33% for LDCT and 15% for chest x-ray.[48] Forty cancers in the LDCT arm (48% were stage I) and 20 in the chest x-ray arm (40% were stage I) were diagnosed during the study period. A total of 16 stage III to stage IV cancers were observed in the LDCT arm versus nine in the chest x-ray arm. Almost all patients with positive screening results received at least one follow-up diagnostic procedure (98% in the LDCT arm and 96% in the chest x-ray arm). This information proved the feasibility of the National Lung Screening Trial (NCI-NLST).[49,50]

The NCI has conducted the NLST, a randomized controlled trial designed to determine whether annual screening with LDCT can reduce lung cancer mortality among persons at elevated risk for that disease (NCI-NLST). More than 50,000 persons aged 55 to 74 years with a history of heavy or long-term smoking have been enrolled in NLST, and the trial is now closed to further recruitment. Participants in NLST were randomly assigned to receive either three annual LDCTs or three annual chest x-rays. Data collection and analysis in NLST are scheduled to continue for 8 years (NCI-NLST).


1. Boucot KR, Weiss W: Is curable lung cancer detected by semiannual screening? JAMA 224 (10): 1361-5, 1973.
2. An evaluation of radiologic and cytologic screening for the early detection of lung cancer: a cooperative pilot study of the American Cancer Society and the Veterans Administration. Cancer Res 26 (10): 2083-121, 1966.
3. Nash FA, Morgan JM, Tomkins JG: South London Lung Cancer Study. Br Med J 2 (607): 715-21, 1968.
4. Brett GZ: The value of lung cancer detection by six-monthly chest radiographs. Thorax 23 (4): 414-20, 1968.
5. Brett GZ: Earlier diagnosis and survival in lung cancer. Br Med J 4 (678): 260-2, 1969.
6. Dales LG, Friedman GD, Collen MF: Evaluating periodic multiphasic health checkups: a controlled trial. J Chronic Dis 32 (5): 385-404, 1979.
7. Friedman GD, Collen MF, Fireman BH: Multiphasic Health Checkup Evaluation: a 16-year follow-up. J Chronic Dis 39 (6): 453-63, 1986.
8. Kubik A, Parkin DM, Khlat M, et al.: Lack of benefit from semi-annual screening for cancer of the lung: follow-up report of a randomized controlled trial on a population of high-risk males in Czechoslovakia. Int J Cancer 45 (1): 26-33, 1990.
9. Wilde J: A 10 year follow-up of semi-annual screening for early detection of lung cancer in the Erfurt County, GDR. Eur Respir J 2 (7): 656-62, 1989.
10. Ebeling K, Nischan P: Screening for lung cancer--results from a case-control study. Int J Cancer 40 (2): 141-4, 1987.
11. Marcus PM: Conflicting evidence in lung cancer screening: randomized controlled trials versus case-control studies. Lung Cancer 41 (1): 37-9, 2003.
12. Sobue T, Suzuki T, Naruke T: A case-control study for evaluating lung-cancer screening in Japan. Japanese Lung-Cancer-Screening Research Group. Int J Cancer 50 (2): 230-7, 1992.
13. Sagawa M, Nakayama T, Tsukada H, et al.: The efficacy of lung cancer screening conducted in 1990s: four case-control studies in Japan. Lung Cancer 41 (1): 29-36, 2003.
14. Fontana RS: Early detection of lung cancer: the Mayo Lung Project. In: Prorok PC, Miller AB, eds.: Screening for Cancer, I: General Principles on Evaluation of Screening for Cancer and Screening for Lung, Bladder, and Oral Cancer. Vol. 78, Geneva, Switzerland: International Union Against Cancer, 1984, pp 107-122.
15. Fontana RS: Screening for lung cancer. In: Miller AB, ed.: Screening for Cancer. New York, NY: Academic Press, 1985, pp 377-395.
16. Fontana RS: Screening for lung cancer: recent experience in the United States. In: Hansen HH, ed.: Lung Cancer: Basic and Clinical Aspects. Boston, Ma: Martinus Nijhoff Publishers, 1986, pp 91-111.
17. Levin ML, Tockman MS, Frost JK, et al.: Lung cancer mortality in males screened by chest X-ray and cytologic sputum examination: a preliminary report. Recent Results Cancer Res 82: 138-46, 1982.
18. Stitik FP, Tockman MS: Radiographic screening in the early detection of lung cancer. Radiol Clin North Am 16 (3): 347-66, 1978.
19. Stitik FP, Tockman MS, Khouri NF: Chest radiology. In: Miller AB, ed.: Screening for Cancer. New York, NY: Academic Press, 1985, pp 163-191.
20. Tockman MS, Levin ML, Frost JK, et al.: Screening and detection of lung cancer. In: Aisner J, ed.: Lung Cancer. New York, NY: Churchill Livingstone, 1985, pp 25-40.
21. Melamed MR, Flehinger BJ, Zaman MB, et al.: Detection of true pathologic stage I lung cancer in a screening program and the effect on survival. Cancer 47 (5 Suppl): 1182-7, 1981.
22. Melamed MR, Flehinger BJ, Zaman MB, et al.: Screening for early lung cancer. Results of the Memorial Sloan-Kettering study in New York. Chest 86 (1): 44-53, 1984.
23. Marcus PM, Bergstralh EJ, Fagerstrom RM, et al.: Lung cancer mortality in the Mayo Lung Project: impact of extended follow-up. J Natl Cancer Inst 92 (16): 1308-16, 2000.
24. Marcus PM, Bergstralh EJ, Zweig MH, et al.: Extended lung cancer incidence follow-up in the Mayo Lung Project and overdiagnosis. J Natl Cancer Inst 98 (11): 748-56, 2006.
25. Thun MJ, Lally CA, Flannery JT, et al.: Cigarette smoking and changes in the histopathology of lung cancer. J Natl Cancer Inst 89 (21): 1580-6, 1997.
26. Gazdar AF, Minna JD: Cigarettes, sex, and lung adenocarcinoma. J Natl Cancer Inst 89 (21): 1563-5, 1997.
27. Black WC: Overdiagnosis: An underrecognized cause of confusion and harm in cancer screening. J Natl Cancer Inst 92 (16): 1280-2, 2000.
28. Gohagan JK, Prorok PC, Kramer BS, et al.: The Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial of the National Cancer Institute. Cancer 75(Suppl 7): 1869-1873, 1995.
29. Oken MM, Marcus PM, Hu P, et al.: Baseline chest radiograph for lung cancer detection in the randomized Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. J Natl Cancer Inst 97 (24): 1832-9, 2005.
30. Ahrendt SA, Chow JT, Xu LH, et al.: Molecular detection of tumor cells in bronchoalveolar lavage fluid from patients with early stage lung cancer. J Natl Cancer Inst 91 (4): 332-9, 1999.
31. Henschke CI, McCauley DI, Yankelevitz DF, et al.: Early Lung Cancer Action Project: overall design and findings from baseline screening. Lancet 354 (9173): 99-105, 1999.
32. Manser RL, Irving LB, de Campo MP, et al.: Overview of observational studies of low-dose helical computed tomography screening for lung cancer. Respirology 10 (1): 97-104, 2005.
33. Ashraf H, Tønnesen P, Holst Pedersen J, et al.: Effect of CT screening on smoking habits at 1-year follow-up in the Danish Lung Cancer Screening Trial (DLCST). Thorax 64 (5): 388-92, 2009.
34. Mastrangelo G, Ballarin MN, Bellini E, et al.: Feasibility of a screening programme for lung cancer in former asbestos workers. Occup Med (Lond) 58 (3): 175-80, 2008.
35. MacRedmond R, Logan PM, Lee M, et al.: Screening for lung cancer using low dose CT scanning. Thorax 59 (3): 237-41, 2004.
36. Swensen SJ, Jett JR, Hartman TE, et al.: Lung cancer screening with CT: Mayo Clinic experience. Radiology 226 (3): 756-61, 2003.
37. Diederich S, Wormanns D, Semik M, et al.: Screening for early lung cancer with low-dose spiral CT: prevalence in 817 asymptomatic smokers. Radiology 222 (3): 773-81, 2002.
38. Swensen SJ, Jett JR, Hartman TE, et al.: CT screening for lung cancer: five-year prospective experience. Radiology 235 (1): 259-65, 2005.
39. Jacobs PC, Mali WP, Grobbee DE, et al.: Prevalence of incidental findings in computed tomographic screening of the chest: a systematic review. J Comput Assist Tomogr 32 (2): 214-21, 2008 Mar-Apr.
40. Chan CK, Wells CK, McFarlane MJ, et al.: More lung cancer but better survival. Implications of secular trends in "necropsy surprise" rates. Chest 96 (2): 291-6, 1989.
41. Dammas S, Patz EF Jr, Goodman PC: Identification of small lung nodules at autopsy: implications for lung cancer screening and overdiagnosis bias. Lung Cancer 33 (1): 11-6, 2001.
42. Marcus PM, Fagerstrom RM, Prorok PC, et al.: Screening for lung cancer with helical CT scanning. Clinical Pulmonary Medicine 9 (6): 323-9, 2002.
43. Sone S, Li F, Yang ZG, et al.: Results of three-year mass screening programme for lung cancer using mobile low-dose spiral computed tomography scanner. Br J Cancer 84 (1): 25-32, 2001.
44. Li F, Sone S, Abe H, et al.: Low-dose computed tomography screening for lung cancer in a general population: characteristics of cancer in non-smokers versus smokers. Acad Radiol 10 (9): 1013-20, 2003.
45. Hasegawa M, Sone S, Takashima S, et al.: Growth rate of small lung cancers detected on mass CT screening. Br J Radiol 73 (876): 1252-9, 2000.
46. Patz EF Jr, Goodman PC, Bepler G: Screening for lung cancer. N Engl J Med 343 (22): 1627-33, 2000.
47. Swensen SJ: CT screening for lung cancer. AJR Am J Roentgenol 179 (4): 833-6, 2002.
48. Croswell JM, Baker SG, Marcus PM, et al.: Cumulative incidence of false-positive test results in lung cancer screening: a randomized trial. Ann Intern Med 152 (8): 505-12, W176-80, 2010.
49. Gohagan JK, Marcus PM, Fagerstrom RM, et al.: Final results of the Lung Screening Study, a randomized feasibility study of spiral CT versus chest X-ray screening for lung cancer. Lung Cancer 47 (1): 9-15, 2005.
50. Gohagan J, Marcus P, Fagerstrom R, et al.: Baseline findings of a randomized feasibility trial of lung cancer screening with spiral CT scan vs chest radiograph: the Lung Screening Study of the National Cancer Institute. Chest 126 (1): 114-21, 2004.

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Changes to This Summary (07 / 15 / 2011)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.


Updated statistics with estimated new cases and deaths for 2011 (cited American Cancer Society as reference 1).

Questions or Comments About This Summary

If you have questions or comments about this summary, please send them to through the Web site's Contact Form. We can respond only to email messages written in English.

More Information

About PDQ

  • PDQ® - NCI's Comprehensive Cancer Database.
    Full description of the NCI PDQ database.

Additional PDQ Summaries

  • PDQ® Cancer Information Summaries: Adult Treatment
    Treatment options for adult cancers.
  • PDQ® Cancer Information Summaries: Pediatric Treatment
    Treatment options for childhood cancers.
  • PDQ® Cancer Information Summaries: Supportive and Palliative Care
    Side effects of cancer treatment, management of cancer-related complications and pain, and psychosocial concerns.
  • PDQ® Cancer Information Summaries: Screening/Detection (Testing for Cancer)
    Tests or procedures that detect specific types of cancer.
  • PDQ® Cancer Information Summaries: Prevention
    Risk factors and methods to increase chances of preventing specific types of cancer.
  • PDQ® Cancer Information Summaries: Genetics
    Genetics of specific cancers and inherited cancer syndromes, and ethical, legal, and social concerns.
  • PDQ® Cancer Information Summaries: Complementary and Alternative Medicine
    Information about complementary and alternative forms of treatment for patients with cancer.


This information is intended mainly for use by doctors and other health care professionals. If you have questions about this topic, you can ask your doctor, or call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

About This PDQ Summary

Purpose of This Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about lung cancer screening. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.

Reviewers and Updates

This summary is reviewed regularly and updated as necessary by the PDQ Screening and Prevention Editorial Board. Board members review recently published articles each month to determine whether an article should:

  • be discussed at a meeting,
  • be cited with text, or
  • replace or update an existing article that is already cited.

Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.

Any comments or questions about the summary content should be submitted to through the Web site's Contact Form. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.

Levels of Evidence

Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Screening and Prevention Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.

Permission to Use This Summary

PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as "NCI's PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary]."

The preferred citation for this PDQ summary is:

National Cancer Institute: PDQ® Lung Cancer Screening. Bethesda, MD: National Cancer Institute. Date last modified <MM/DD/YYYY>. Available at: Accessed <MM/DD/YYYY>.

Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.


The information in these summaries should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on on the Coping with Cancer: Financial, Insurance, and Legal Information page page.

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Last Revised: 2011-07-22

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