NCI Investigates Causes of Tobacco Usage and Addiction

Every 3 years, the National Cancer Institute (NCI) asks researchers, advisory panels, and advocacy groups to recommend "extraordinary opportunities for investment," which it defines as "broad-based, overarching areas of scientific pursuit that hold tremendous promise for significantly expanding our understanding of cancer."

This is the fourth in a series of interviews exploring the progress and promise of NCI’s six current extraordinary opportunities: Genes and the environment (January 2002); cancer imaging (February 2002); defining the signature of cancer cells (May 2002); molecular targets of prevention and treatment; research on tobacco and tobacco-related cancers (below); and cancer communications.

BETHESDA, Maryland—In 1998, the National Cancer Institute expanded its role in the investigation of tobacco, with a larger focus on understanding its use and the mechanism of nicotine addiction. The new effort, in both intramural and extramural research, has emphasized an interdisciplinary approach that includes experts in such fields as epidemiology, psychology, and working with ethnic minority populations.

ONI Washington bureau chief Patrick Young discussed the NCI program with Robert Croyle, PhD, associate director for behavioral research, Division of Cancer Control and Population Sciences, and Scott Leischow, PhD, chief of the division’s Tobacco Control Research Branch.

ONI: Tobacco has been explored extensively. What questions could possibly be left to answer?

Dr. Croyle: Quite a few. People still smoke, kids are still taking up smoking, and we still have a large industry that is heavily marketing a product that is a major cause of preventable death. We have clearly made progress, but there is much more we need to know about the addiction process and how to more effectively prevent tobacco use and help people quit.

ONI: Why does NCI see an "unprecedented opportunity" to reduce the disease burden of tobacco?

Dr. Croyle: We have seen a great deal of progress in disciplines relevant to studying tobacco use, such as behavioral science, pharmacology, addiction research, genetic susceptibility, and research at the population and community levels. We see an opportunity to bring together several diverse fields to develop a more comprehensive biobehavioral model of tobacco use, which could then inform areas such as drug development for the treatment of nicotine addiction and more effective programs to prevent tobacco use.

Dr. Leischow: What makes this area of research different from other NCI efforts is that we are dealing with a cancer-causing agent that is legal and marketed widely. It is always a challenge for us to move the science forward without it getting slowed down or diverted by political issues or by industry efforts to undermine the credibility of the science.

ONI: How much will NCI spend for tobacco-related research in fiscal year 2002?

Dr. Croyle: We don’t have a precise estimate, but last fiscal year, we spent a little more than $80 million.

ONI: What types of tobacco research does NCI support?

Dr. Croyle: One of the largest and newest programs is our Transdisciplinary Tobacco Use Research Centers, the first NCI centers program that is specifically focused on tobacco use. It is an important initiative because it is also a collaborative one. Clearly, tobacco use is not relevant just to cancer but to a whole range of diseases, including heart disease, stroke, and emphysema. This initiative is co-funded with the National Institute on Drug Abuse [NIDA] and the Robert Wood Johnson Foundation.

ONI: Do you work actively with NIDA?

Dr. Croyle: NIDA is one of our most important collaborators within the NIH. It funds much of the basic science research on drug addiction, including nicotine addiction. NIDA also funds work on tobacco use and tobacco-use prevention.

ONI: What new insights are emerging about tobacco addiction?

Dr. Leischow: One area is a greater understanding of the genetic basis of addiction, the commonalities that occur across multiple addictions, and their roles in leading to disease. Another area is the role of media influences on initiation and continued use of tobacco. To understand the long-term impact of tobacco use, we need to understand how it is being sold and marketed to individuals.

ONI: What about the behavioral sciences?

Dr. Croyle: We have a large portfolio in behavioral research, especially in the area of youth tobacco use. One of our largest proactive programs right now concerns the prevention of youth tobacco use and the development of methods to help teenagers quit.

Dr. Leischow: The interrelationship between behavior and biology is really very important and very complex. That is, if some kids are more prone biologically to addiction, it is important for us to understand if and how that translates into the activities that would put them at even greater risk.

ONI: Youth smoking has dropped from about 37% in 1997 to around 32%. Do you view that as the glass half full or half empty?

Dr. Leischow: We need to look at it both ways. We saw an increase in adolescent tobacco use in the 1990s, and so it is gratifying to see the numbers starting to drop. At the same time, it is very clear that we have a long way to go to prevent tobacco use in children and to help them quit. The vast majority of all adult smokers began smoking by the age of 18. At last count, we had 38 grants that are looking at adolescent tobacco use.

ONI: What are the major issues of smoking initiation that NCI is addressing?

Dr. Leischow: We are interested in understanding social influences on tobacco use by peers, family, and the media. Those three alone are complex and interacting in ways that, quite frankly, we don’t fully understand.

We are funding research looking at understanding the etiology of addiction and how it actually takes hold in an individual. We are funding a number of studies looking at methods to help kids quit, both behavioral methods and pharmacological approaches, such as using Zyban [bupropion], and at school-based approaches that are oriented toward larger groups.

There is much for us to learn because, until a few years ago, there was almost no research in this area.

Dr. Croyle: We have changed our conceptualization of the problem to a much broader view. We now realize that in addition to understanding the biological and behavioral factors in tobacco use, it is critical to look at policies, such as smoke-free workplaces or taxes on tobacco use, for example, and we are now funding this research. We have also reached out to an area of new research using the tobacco company documents that were released in the litigation against the industry. We are still uncovering information from these documents.

ONI: Have you been able to show that NCI’s effort has had any impact as yet?

Dr. Croyle: The next few years will be key. We have developed and funded several new research initiatives, and we are just starting to see some of the evidence generated from them in terms of publications.

So the next 3 to 5 years is really the window in which you are going to see a wealth of new evidence being generated by the Tobacco Use Research Centers, by the youth tobacco research programs, and by other new initiatives in chemopreven-tion, biomarkers, and the policy area.

Dr. Leischow: Another challenge is to keep the issue on people’s radar screens as a continued health risk. We have some products that work moderately well to help people quit using tobacco and they are marketed heavily. Sometimes, people think we have a solution to the tobacco problem. In fact, we don’t. We are not even close to solving it or reducing tobacco-related cancers.

ONI: What about the future?

Dr. Croyle: There is a new issue on the horizon that we have discussed with policymakers and researchers. Tobacco products are constantly changing and evolving as the industry develops new ways to deliver nicotine that have unknown health effects. We are trying to stay ahead of the curve; we are going to have to expend a great deal of effort to catch the science up with the evolution of these new products.

Dr. Leischow: One ad for a new cigarette claims it has a low cancer risk. Will that cause people to not want to quit? Will it cause people who don’t smoke to take up smoking? It is our responsibility to keep up with that evolving field and not wait 20 years after the fact to jump on these issues after we see the health effects of these new products.