Of course, early detection of lung cancer by chest x-ray was shown, decades ago, to have no impact on mortality and is often the example of "lead time bias" taught in evidence-based medicine lectures.
But now we've got computer-aided tomography scanners, with their improved resolution (and higher doses of radiation). Can they find lung cancer soon enough to treat? Will they find "incidentalomas" that prompt dangerous, useless workups? Will this intervention do more harm than help?
These are serious questions, and research is ongoing. Some provocative recent results suggesting CT scans of asymptomatic at-risk individuals (mostly smokers over 40) can improve lung cancer mortality, but others offer some words of caution going forward.
Sadly, the folks at demandaCATscan.org think they've got all the evidence they need. On their front page, it's written:
The availability of early detection for lung cancer is widely unknown, inexcusably underencouraged, underfunded, and underinsured. Just ask five-out-of-five lung cancer survivors. “While we wait for the cure, the biomarkers, the blood and saliva tests, we will use the early detection imaging and diagnostic tool we have available, right now. The 64-slice low dose CT scan."
One of the participating hospitals, linked from the demandaCATscan.org site, is honest about the trial:
Sequoia’s lung cancer early detection program is a participating member of the International Early Lung Cancer Action Program (I-ELCAP).
I-ELCAP is the first research study of its kind involving a large number of hospitals that are evaluating the effectiveness of screening for lung cancer with low-dose CT Scanning...
...Who should get screened? We currently do not know what defines the ideal population for lung cancer screening (that is one of the goals of the study). Our screening program includes people 40 and over with a history of smoking or second hand smoke exposure.
Reasonable words. And looking around the site that demandaCATscan points to, thelungcancerfoundation.org, I see a medical advisory board full of oncologists, thoracic surgeons, and indeed, the author of the aforementioned 2006 NEJM study touting early detection via CT. Several board members are themselves lung cancer survivors.
I can't doubt this group's dedication or integrity (I originally expected "demandaCATscan.org" would be backed by GE Lightspeed scanners or something similar).
But I must ask, were these board members behind the subway ad campaign? Do they really want the general public demanding a CT scan? Because it's hard to believe such an informed and experienced group could endorse this approach.
I could have supported ads targeted to smokers over 40, encouraging them to enroll in a lung cancer screening trial. But the way it's currently executed, these ads will plant a lot of misconceptions in peoples' minds, and lead to a lot of fruitless conversations with already time-crunched physicians. Plus, the money spent misguiding young healthy subway riders could've been spent better -- on researching screening, therapies, or just enrolling appropriate subjects.
It seems like this intervention will cause more harm than benefit.