Ugly Turn in Lung Cancer Screening Controversy

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March 26, 2008 - 9:56 pm email to a friend printer friendly view / write comments

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Dr. West

Thanks to member Carlos for bringing to our attention a high profile article in the New York Times today about some controversy now surrounding the Early Lung Cancer Action Project (ELCAP) trial, probably the most influential study of CT screening that has been done. Let me disclose immediately that my own institution, Swedish Hospital in Seattle, is a participating site in ongoing CT screening work led by Dr. Claudia Henschke and the group at Cornell Weill Medical School in New York.

It’s hard not to discuss the idea of CT screening for lung cancer without mentioning Dr. Henschke, who I would say has been the leading and most visible proponent of lung cancer screening in the entire medical community. She has led work in this field for many years, and her paper published in late 2006 (abstract here) reported an 88% 10-year survival, remarkably different from the typical overall survival for lung cancer without screening, which is closer to 15%. And while many experts noted major flaws in extrapolating that one could expect anything close to that in the real world, the trial represents one of the strongest points in favor of CT screening for lung cancer.

The brouhaha stems from the new discovery that much of this work, particularly early on, back in 2000 or so, was actually being funded by the tobacco industry, and there’s some suspicion that the leaders at Cornell may have been less than forthright about the source of funding, since the tobacco money was used to start a new foundation that was not appreciated to have been tied to the tobacco industry.

And why would the tobacco industry have a stake in this? Presumably, if people felt reassured that we can detect lung cancer early enough to cure it most of the time, people would feel less of a compulsion to stop smoking, or maybe even pick it up as a habit. Yikes.

The article is replete with a who’s who among leaders in lung cancer, cancer in general, and medical publishing, sharing grave concern that this connection compromises if not necessarily discredits the credibility of this work. I’m not sure I’d be that heavy handed about it. Others referred to it as blood money, but I think we should be dscussing the validity or shortcomings of the data. I’ll say that while I think there’s a real possibility, and I’d even say probability, that CT screening really would/does improve survival, I don’t think lung cancer survival would soar to 75% or higher. I do believe that the ELCAP study probably enriches for more indolent cancer — it didn’t really pick up SCLC, probably because screening is better suited for detection of slower cancers than rapidly growing ones. I suspect some very threatening lung cancers would be caught much earlier than they would if diagnosis only occurred at the time of symptoms appearing, but I think there would also be a stunning rise in the number of cases of well differentiated adenocarcinomas/bronchioloalveolar carcinomas (BACs) that can behave in a very indolent way and may not have a strong impact on improving survival.

The other point the article raises is that Dr. Henschke and Dr. Yankelovitz, another CT screening proponent, work closely with GE and stand to gain financially from the widespread adoption of CT screening for lung cancer. This doesn’t mean that they would falsify data, but some would argue that it drmatically alters their ability to speak to the evidence objectively. And several people suggested that between the support from the tobacco industry and the conflicts of interest, their work would not have been accepted into such a high profile and credible journal as the New England Journal of Medicine had these financial associations been more transparent.

In my own mind, this doesn’t significantly change my view of the complex topic of lung cancer screening. I think it should cause people who reflexively consider CT screening to be incontrovertibly and unquestionably beneficial to re-examine whether the issue is really that straightforward. It’s important to know who stands to gain from what when interpreting the arguments that people make. I think Dr. Henchke is a true believer in CT screening and that there is enough evidence to feel that screening is compelling, but this issue was a big blow to the credibility of the movement. Politics makes strange bedfellows, but whenever you have lung cancer leadership in partnership with the tobacco industry, we need to take a step back and carefully consider what’s going on.

I welcome people’s thoughts.

Posted in: General, Lung Cancer, Screening Issues and Controversy                     email to a friend printer friendly