How big are the mortality reductions produced by cancer screening? Why do so many trials say 20%?
November 1, 2011 @ 3:30 - 4:30 pm
James Hanley, Ph.D., McGill University
Location: Blockley Hall - Room 701
TITLE: How big are the
mortality reductions produced by cancer screening?
Why do so many trials say 20%?
Abstract:Influential reports on the reductions produced by screening for cancers of the prostate, colon and lung have appeared recently. The reported reductions in these randomized trials have been modest, and smaller than expected. But even more surprisingly, all three figures are very similar. I explain why these figures are underestimates and why the seemingly-universal 20% reduction is an artifact of the prevailing data-analysis methods and stopping rules. A different approach to the analysis of data from cancer screening trials is called for.