A class-action lawsuit was filed yesterday in a New York federal district court on behalf of all 50+ year-old smokers in New York State who smoked at least one pack per day of Marlboro cigarettes for at least 20 years. The lawsuit is unusual in that it doesn't seek damages for harms done to the smokers, but instead asks Philip Morris (maker of Marlboro) to pay for a screening program intended to provide early detection of lung cancer among this group of smokers.
Specifically, the lawsuit apparently asks the Court to require Philip Morris to pay for annual, low-dose spiral CT scans of all of the smokers in this class. Further tests (such as biopsies) needed to confirm the diagnosis of lung cancer, as well as surgery, if needed, would presumably be covered by the smokers' traditional insurance programs, although it is not clear to me whether insurance companies would pay for follow-up tests required due to a tobacco industry-funded screening program.
The lawsuit apparently contends that this screening program will benefit the class members, estimated in the tens of thousands, by providing early diagnosis of lung cancer at a stage that is more treatable.
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There's just one problem with this lawsuit: as of yet, there is simply not an early detection program that has been shown to both reduce lung cancer mortality and to be sufficiently specific (i.e., to have a low enough rate of false positives) so as to present benefits that outweigh the costs of the screening program in terms of the false positive diagnosis rate and the need to intervene with intensive and invasive procedures on a huge proportion of patients who do not in fact have disease.
For this reason, no major medical organization has recommended low-dose CT screening as an effective tool for the early detection of lung cancer on a population basis.
The problem is that low-dose spiral CT scans, in the current form available in most hospitals, has an extremely low positive predictive value. In other words, the proportion of patients with a nodule detected on CT scan who actually have lung cancer is extremely low. The overwhelming majority of patients with an abnormal CT scan do not, in fact, have lung cancer.
But the presence of an abnormal CT scan requires intensive and possibly, invasive follow-up tests, including the possibility of a lung biopsy, in order to rule out lung cancer. Plus, the finding of a nodule on a CT scan is going to certainly create a huge amount of anxiety for these smokers, and for many of them, they will have to live with this anxiety because the recommendation will be to simply have them come back in 6 months or a year for another CT to see if the nodule has grown.
If I were a smoker, I don't think I would want to be told that I have a nodule in my lung that could be lung cancer, but that the doctors aren't going to do anything about it except wait for a year to see if it grows. I would be absolutely freaking out.
And the reality is that the majority of smokers screened by such a program would be in exactly this situation.
Medical screening is a wonderful thing and it can save lives, but if done indiscriminately, or in situations where a sufficiently specific test is not available (especially if combined with the low prevalence of the disease being detected), it can result in a lot of harm. And the balance of harm to good can actually lie on the harm side.
In the case of low-dose spiral CT scans for early detection of lung cancer, the balance right now, in my opinion at least, lies on the side of more harm than good. And this is why no medical organization has recommended this procedure as an effective screening test for lung cancer.
I am not suggesting that low-dose CT scans will not ever become an effective screening test, or that there will not at some point (possibly very soon) be evidence that the procedure does reduce mortality. I am just stating that right now, there is not sufficient evidence that the procedure will indeed save lives, and there is certainly not evidence that the benefits of instituting this screening procedure on a large population of tens of thousands of smokers would result in more good than harm.
I think it's going to be difficult to convince a jury otherwise.