Methodologic Barriers to Addressing Critical Questions About Tobacco and Cancer Prognosis

Cigarette smoking has been causally linked to cancer for decades, and we now know a great deal about its impact on primary cancer incidence in the lung and a growing list of other organ sites. However, the evidence regarding the effects of cigarette smoking and other tobacco use on subsequent prognosis is by no means complete. The article by Gillison et al that accompanies this editorial reports an increased risk of progression and death associated with cigarette smoking duration and intensity among patients with oropharyngeal cancer. This is important information to add to our growing understanding of smoking as a risk factor for clinical outcomes after diagnosis with cancer. The article also provides an opportunity to discuss several challenges—methodologic and otherwise—that are frequently barriers to capturing the data needed in studies of cigarette smoking and cancer prognosis.