In bed with the enemy?

We learned last week that Dr. Claudia Henschke of Weill Cornell Medical College apparently received $3.6 million in grants from the Liggett Group, a cigarette manufacturer, for her work in CT screening for lung cancer. In addition, The Cancer Letter reported that Dr. Henschke and Dr. David Yankelevitz, also of Weill Cornell, failed to disclose in articles and educational lectures a patent and 10 pending patents related to CT screening and follow-up. The implication is that they stood to make significant financial gains if CT screening were approved as a result of their patents.

Here are some of my calculations based on the reported results from the ELCAP trial (Early Lung Cancer Action Project) published in The New England Journal of Medicine:

Screened: 31,567 asymptomatic at-risk patients with low-dose CT

True Positives from screening: 479 (they report 484 because an additional five patients were diagnosed after symptoms developed, which I exclude in my calculations as those patients technically were not detected by screening but rather by a diagnostic study as a result of symptoms)

All Positives: 5,646

Thus the positive predictive value (PPV) is:
True Positives/ (True Positives + False Positives) = 479/ 479 + 5,167 = 8.4%

Specificity is:
True Negatives/ (False Positives + True Negatives) = 25,926/ 5,167 + 25,921 = 83%

The results of ELCAP were not adopted into practice for many reasons, among them the low PPV meaning that >90% of positive tests were in patients who did not have lung cancer. The medical community appropriately scrutinized these results and decided not to endorse mass screening of at-risk patients at this time.

While the unveiling of these conflicts of interest raises too many problems to mention here, my first question is: why would a tobacco company fund a screening trial in lung cancer?