Lung cancer: Difference between revisions
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In 2004, a clinical practice guideline by the [http://www.ahrq.gov/clinic/uspstfix.htm U.S. Preventive Services Task Force (USPSTF)] gave a [http://www.ahrq.gov/clinic/3rduspstf/ratings.htm grade I recommendation] indicating that "the evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer".<ref name="pmid15126258">{{cite journal |author=U.S. Preventive Services Task Force |title=Lung cancer screening: recommendation statement |journal=Ann. Intern. Med. |volume=140 |issue=9 |pages=738-9 |year=2004 |pmid=15126258 |doi=|url=http://www.annals.org/cgi/content/full/140/9/738}}</ref><ref name="pmid15126259">{{cite journal |author=Humphrey LL, Teutsch S, Johnson M |title=Lung cancer screening with sputum cytologic examination, chest radiography, and computed tomography: an update for the U.S. Preventive Services Task Force |journal=Ann. Intern. Med. |volume=140 |issue=9 |pages=740-53 |year=2004 |pmid=15126259 |doi=|url=http://www.annals.org/cgi/content/full/140/9/740}}</ref> | In 2004, a clinical practice guideline by the [http://www.ahrq.gov/clinic/uspstfix.htm U.S. Preventive Services Task Force (USPSTF)] gave a [http://www.ahrq.gov/clinic/3rduspstf/ratings.htm grade I recommendation] indicating that "the evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer".<ref name="pmid15126258">{{cite journal |author=U.S. Preventive Services Task Force |title=Lung cancer screening: recommendation statement |journal=Ann. Intern. Med. |volume=140 |issue=9 |pages=738-9 |year=2004 |pmid=15126258 |doi=|url=http://www.annals.org/cgi/content/full/140/9/738}}</ref><ref name="pmid15126259">{{cite journal |author=Humphrey LL, Teutsch S, Johnson M |title=Lung cancer screening with sputum cytologic examination, chest radiography, and computed tomography: an update for the U.S. Preventive Services Task Force |journal=Ann. Intern. Med. |volume=140 |issue=9 |pages=740-53 |year=2004 |pmid=15126259 |doi=|url=http://www.annals.org/cgi/content/full/140/9/740}}</ref> | ||
==Studies of efficacy== | |||
Regular [[chest radiography]] and [[sputum]] examination programs were not effective in reducing mortality from lung cancer.<ref name="pmid14973979">{{cite journal |author=Manser RL, Irving LB, Stone C, Byrnes G, Abramson M, Campbell D |title=Screening for lung cancer |journal=Cochrane database of systematic reviews (Online) |volume= |issue=1 |pages=CD001991 |year=2004 |pmid=14973979 |doi=10.1002/14651858.CD001991.pub2}}</ref> Previous studies (Mayo Lung Project and Czechoslovakia lung cancer screening study, combining over 17,000 smokers) had shown that early detection of lung cancer was possible with such programs, but mortality was not improved. Simply detecting a tumor at an earlier stage may not necessarily lead to improved survival. For example, plain chest X-ray screening resulted in increased time from diagnosis of cancer until death and those cancers being detected by screening tended to be earlier stages. However, these patients continued to die at the same rate as those who are not screened. At present, no professional or specialty organization advocates screening for lung cancer outside of [[clinical trial]]s. | |||
A [[computed tomography]] (CT) scan can uncover tumors not yet visible on an X-ray. CT scanning is now being actively evaluated as a screening tool for lung cancer in high risk patients, and it is showing promising results. The [[United States]] [[National Cancer Institute]] is currently completing a randomized trial comparing CT scans with chest radiographs. with results expected in 2010. Several single-institution trials are ongoing around the world. | |||
The International Early Lung Cancer Action Project published the results of CT screening on over 31,000 high-risk patients in late 2006 in the ''[[New England Journal of Medicine]]''.<ref name="pmid17065637">{{cite journal |author=Henschke CI, Yankelevitz DF, Libby DM, Pasmantier MW, Smith JP, Miettinen OS |title=Survival of patients with stage I lung cancer detected on CT screening |journal=N. Engl. J. Med. |volume=355 |issue=17 |pages=1763-71 |year=2006 |pmid=17065637 |doi=10.1056/NEJMoa060476}}</ref> In this study, 85% of the 484 detected lung cancers were stage I and thus highly treatable. Mathematically these stage I patients would have an expected 10-year survival of 88%. However, there was no randomization of patients (all received CT scans and there was no comparison group receiving only x-rays) and the patients were not actually followed out to 10 years post detection (the median followup was 40 months). Additional controversy surrounded the study after a 2008 ''[[New York Times]]'' report found that it had been funded indirectly by the parent company of the [[Liggett Group]], a [[tobacco company]]; the use of tobacco industry funds was not disclosed in the paper.<ref name="nytimes">[http://www.nytimes.com/2008/03/26/health/research/26lung.html?pagewanted=1&_r=1&hp Cigarette Company Paid for Lung Cancer Study], by Gardiner Harris. Published in the ''[[New York Times]]'' on [[March 26]] [[2008]]. Accessed [[March 26]] [[2008]].</ref> | |||
In contrast, a March 2007 study in the ''[[Journal of the American Medical Association]]'' (JAMA) found no mortality benefit from CT-based lung cancer screening.<ref name="pmid17341709">{{cite journal |author=Bach PB, Jett JR, Pastorino U, Tockman MS, Swensen SJ, Begg CB |title=Computed tomography screening and lung cancer outcomes |journal=JAMA |volume=297 |issue=9 |pages=953-61 |year=2007 |pmid=17341709 |doi=10.1001/jama.297.9.953}}</ref> 3,200 current or former smokers were screened for 4 years and offered 3 or 4 CT scans. Lung cancer diagnoses were 3 times as high, and surgeries were 10 times as high, as predicted by a model, but there were no significant differences between observed and expected numbers of advanced cancers or deaths.<ref name=Crestanello_2004>{{cite journal |author=Crestanello JA, Allen MS, Jett J, Cassivi SD, et al. |title=Thoracic surgical operations in patients enrolled in a computed tomographic screening trial |journal=Journal of Thoracic and Cardiovascular Surgery |volume=128 |issue=2 |pages=254-259 |year=2004 |pmid=15282462}}</ref> | |||
Randomized controlled studies are underway in this area to see if decreased long-term mortality can be directly observed from CT screening.<ref name="pmid15603850">{{cite journal |author=Gohagan JK, Marcus PM, Fagerstrom RM, ''et al'' |title=Final results of the Lung Screening Study, a randomized feasibility study of spiral CT versus chest X-ray screening for lung cancer |journal=Lung Cancer |volume=47 |issue=1 |pages=9-15 |year=2005 |pmid=15603850 |doi=10.1016/j.lungcan.2004.06.007}}</ref> | |||
==References== | ==References== | ||
<references/> | <references/> | ||
Revision as of 15:42, 4 April 2008
Screening
Practice guidelines
Clinical practice guidelines issued by the American College of Chest Physicians in 2007 recommended against routine screening for lung cancer because of a lack of evidence that such screening was effective.[1]
In 2004, a clinical practice guideline by the U.S. Preventive Services Task Force (USPSTF) gave a grade I recommendation indicating that "the evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer".[2][3]
Studies of efficacy
Regular chest radiography and sputum examination programs were not effective in reducing mortality from lung cancer.[4] Previous studies (Mayo Lung Project and Czechoslovakia lung cancer screening study, combining over 17,000 smokers) had shown that early detection of lung cancer was possible with such programs, but mortality was not improved. Simply detecting a tumor at an earlier stage may not necessarily lead to improved survival. For example, plain chest X-ray screening resulted in increased time from diagnosis of cancer until death and those cancers being detected by screening tended to be earlier stages. However, these patients continued to die at the same rate as those who are not screened. At present, no professional or specialty organization advocates screening for lung cancer outside of clinical trials.
A computed tomography (CT) scan can uncover tumors not yet visible on an X-ray. CT scanning is now being actively evaluated as a screening tool for lung cancer in high risk patients, and it is showing promising results. The United States National Cancer Institute is currently completing a randomized trial comparing CT scans with chest radiographs. with results expected in 2010. Several single-institution trials are ongoing around the world.
The International Early Lung Cancer Action Project published the results of CT screening on over 31,000 high-risk patients in late 2006 in the New England Journal of Medicine.[5] In this study, 85% of the 484 detected lung cancers were stage I and thus highly treatable. Mathematically these stage I patients would have an expected 10-year survival of 88%. However, there was no randomization of patients (all received CT scans and there was no comparison group receiving only x-rays) and the patients were not actually followed out to 10 years post detection (the median followup was 40 months). Additional controversy surrounded the study after a 2008 New York Times report found that it had been funded indirectly by the parent company of the Liggett Group, a tobacco company; the use of tobacco industry funds was not disclosed in the paper.[6]
In contrast, a March 2007 study in the Journal of the American Medical Association (JAMA) found no mortality benefit from CT-based lung cancer screening.[7] 3,200 current or former smokers were screened for 4 years and offered 3 or 4 CT scans. Lung cancer diagnoses were 3 times as high, and surgeries were 10 times as high, as predicted by a model, but there were no significant differences between observed and expected numbers of advanced cancers or deaths.[8]
Randomized controlled studies are underway in this area to see if decreased long-term mortality can be directly observed from CT screening.[9]
References
- ↑ Alberts WM (2007). "Diagnosis and Management of Lung Cancer Executive Summary: ACCP Evidence-Based Clinical Practice Guidelines (2nd Edition)" 132 (3_suppl): 1S–19S. DOI:10.1378/chest.07-1860. PMID 17873156. Research Blogging.
- ↑ U.S. Preventive Services Task Force (2004). "Lung cancer screening: recommendation statement". Ann. Intern. Med. 140 (9): 738-9. PMID 15126258. [e]
- ↑ Humphrey LL, Teutsch S, Johnson M (2004). "Lung cancer screening with sputum cytologic examination, chest radiography, and computed tomography: an update for the U.S. Preventive Services Task Force". Ann. Intern. Med. 140 (9): 740-53. PMID 15126259. [e]
- ↑ Manser RL, Irving LB, Stone C, Byrnes G, Abramson M, Campbell D (2004). "Screening for lung cancer". Cochrane database of systematic reviews (Online) (1): CD001991. DOI:10.1002/14651858.CD001991.pub2. PMID 14973979. Research Blogging.
- ↑ Henschke CI, Yankelevitz DF, Libby DM, Pasmantier MW, Smith JP, Miettinen OS (2006). "Survival of patients with stage I lung cancer detected on CT screening". N. Engl. J. Med. 355 (17): 1763-71. DOI:10.1056/NEJMoa060476. PMID 17065637. Research Blogging.
- ↑ Cigarette Company Paid for Lung Cancer Study, by Gardiner Harris. Published in the New York Times on March 26 2008. Accessed March 26 2008.
- ↑ Bach PB, Jett JR, Pastorino U, Tockman MS, Swensen SJ, Begg CB (2007). "Computed tomography screening and lung cancer outcomes". JAMA 297 (9): 953-61. DOI:10.1001/jama.297.9.953. PMID 17341709. Research Blogging.
- ↑ Crestanello JA, Allen MS, Jett J, Cassivi SD, et al. (2004). "Thoracic surgical operations in patients enrolled in a computed tomographic screening trial". Journal of Thoracic and Cardiovascular Surgery 128 (2): 254-259. PMID 15282462.
- ↑ Gohagan JK, Marcus PM, Fagerstrom RM, et al (2005). "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. DOI:10.1016/j.lungcan.2004.06.007. PMID 15603850. Research Blogging.