The news that a major study on lung cancer screening was generously funded by the tobacco industry has cast doubt on this study's findings and has raised many troubling questions about the nature and extent of industry influence on clinical research. The money came from Liggett Tobacco, and was channeled through an innocent-sounding charity that was set up by Dr. Claudia Henschke, the study's leading author, at Weill Cornell Medical Center.

Last week we began a two-part discussion of the Henschke study, its funding and its controversial conclusions. We conclude that discussion this week. (To read part I of this article, please click or go to:
http://www.cancerdecisions.com/040608.html )

Prevention vs. Detection

Beyond the dangers of over-diagnosis and the attendant risks posed by invasive diagnostic procedures and unwarranted treatments, there is another potential harm inherent in lung cancer screening - and indeed in all cancer screening programs: the risk of confusing screening with prevention. They are not at all the same thing. Prevention is by definition a proactive effort, aimed at determining the causes of cancer and systematically removing them so that cancer does not occur. Screening, on the other hand, is a rearguard action: its intention is not to prevent disease but only to detect it once it is already present.

Why is this harmful? In the case of lung cancer, the causes of the disease are largely known, and preventable. Almost 80 percent of all lung cancer is caused by smoking. We know beyond doubt that if smoking were to stop, deaths from lung cancer would fall precipitously. Given that we know with such certainty how to prevent the loss of more than 130,000 lives each year, it is hard to justify diverting resources into mass lung cancer screening, with no assurance whatever that this will, in fact, save lives or reduce the enormous suffering caused by this most preventable of all cancers.

Tobacco Money - Science for Sale?

Who benefits when resources are diverted from the prevention of lung cancer to its detection? The tobacco companies. Perhaps this is why they chose to invest $3.6 million dollars to support Dr. Claudia Henschke's study, a study which drew unequivocally - many would say unjustifiably - favorable conclusions concerning the effectiveness of lung cancer screening.

It is the convention, when studies are published in the medical and scientific literature, for authors to declare any conflict of interest. Journals also require the authors to cite the names of the institutions which have supported the study, and the grants which have helped fund it. When the Henschke study was published in the New England Journal of Medicine in 2006, the article carried a long list of the funding institutions, including the National Institutes of Health, the Department of Energy, the American Cancer Society and others. Buried in the long list of supporting institutions and foundations was the Foundation for Lung Cancer: Early Detection, Prevention & Treatment.

Now, almost 18 months after the publication of her study, Claudia Henschke has acknowledged publicly that her study was generously funded by the tobacco industry, and that the funds were channeled through this Foundation. According to a front-page article by Gardiner Harris in the New York Times, Dr. Henschke is listed as the Foundation's president. Among the study's co-authors, David Yankelevitz, MD, served as the Foundation's treasurer. The Dean of Weill Cornell Medical College, Antonio Gotto, MD, and the vice-chairman of the Weill Cornell board of overseers, Arthur J. Mahon, served on the Foundation's board of directors. This unsavory relationship came to light when the Times examined the Foundation's tax records (Harris, 2008).

Neither the fact that the Foundation was funded by tobacco money, nor the fact that Dr. Henschke and Dr. Yankelevitz both received royalties from licenses they owned on the spiral CT imaging technology used in the screening study, were declared to the New England Journal of Medicine at the time the study was published. Instead, the study carried the simple, unequivocal statement: "No potential conflict of interest relevant to this article was reported."

That Dr. Henschke's study - a study claiming that 80 percent of the current deaths from lung cancer could be avoided by screening - was supported even in part by the tobacco industry is grounds in its own right to cast doubt on the veracity of her findings. Furthermore, the fact that she and one of her co-authors received royalties from the technology which her study directly endorsed should certainly disqualify the study from publication - which is, presumably, why these facts were withheld from the editors of the New England Journal of Medicine at the time the paper was submitted and published.

The NEJM has now published an official statement that reads, in part:

"The Lung Cancer Screening Group's research was funded by 32 different entities, one of which was the Foundation for Lung Cancer: Early Detection, Prevention and Treatment. It has not been our practice to inquire about the specific sources of funding of foundations such as this. We recently learned, however, that this foundation was headed by the principal investigator of the 2006 study, that it was housed at her academic institution, and that the only contributor during most of its existence was the Vector Group, the parent company of Liggett, a major tobacco company. We and our readers were surprised to learn that the source of the funding of the charitable foundation was, in fact, a large corporation that could have an interest in the study results.

"This situation raises two concerns. First, as medical journal editors, we believe that it is important that the ultimate source of funding be made clear to the Journal's readers. Second, it is appropriate to ask whether a study on clinical outcomes in lung cancer should be directly underwritten in part by the tobacco industry. Given the enormous burden of smoking-related illness and the ongoing sale of cigarettes and other forms of tobacco, one might question the advisability of research entities accepting funding from tobacco companies except through the American Legacy Foundation, which distributes funds received through the Master Settlement Agreement with U.S. tobacco companies" (NEJM, 2008).

There appears to be a contradiction here. On the one hand, the editors say "It has not been our practice to inquire about the specific sources of funding of foundations such as this." On the other hand, they state that they believe "it is important that the ultimate source of funding be made clear to the Journal's readers." Either way, it seems that the honorable thing would be for the Journal to withdraw Henschke's tainted paper entirely. If it fails to do so, the Journal will have forfeited much of its own credibility as the standard-bearer for scientific, evidence-based medicine.

--Ralph W. Moss, Ph.D.

Resources:

Bach PB, Jett JR, Pastorino U, et al. Computed tomography screening and lung cancer outcomes. JAMA 2007;297(9):953-61.

Bach PB, Kelley MJ, Tate RC, McCrory DC. Screening for lung cancer: a review of the current literature. Chest. 2003;123(suppl):72S-82S.

Brenner, DJ. Radiation risks potentially associated with low-dose CT screening of adult smokers for lung cancer. Radiology. 2004;231(2):440-45.

Henschke C, Yankelevits DF, Libby DM, et al. Survival of patients with stage I lung cancer detected on CT screening. N Engl J Med. 2006; 355(17):1763-71.

Harris, Gardiner. Cigarette company paid for lung cancer study. New York Times, Mar 26 2008. Accessed at:
http://www.nytimes.com/2008/03/26/health/research/26lung.html?_r=1&pagewanted=print&oref=slogin

Kolata, Gina. Researchers dispute benefits of CT scans for lung cancer. New York Times, Mar 7 2007.

Schwartz RS, Curfman GD, Morrissey S, et al. Full disclosure and the funding of biomedical research. N Engl J Med. 2008, April 2. Available online at:
http://content.nejm.org/cgi/content/full/NEJMe0802618?query=TOC