Long-term Nicotine Replacement Therapy: Cancer Risk in Context

Abstract

Nicotine replacement therapy (NRT) for up to 12 weeks is well established, safe and efficacious for fostering smoking cessation. Some smokers at a high risk of relapse may benefit from long-term use, and so long-term NRT safety and efficacy have become a paramount question for the FDA and others. Laboratory studies have indicated a carcinogenic potential of nicotine. Animal model studies reported in this issue of the journal by Maier and colleagues (beginning on page 1743) and Murphy and colleagues (beginning on page 1752), however, provide additional reassurance that NRT does not promote lung cancer. Very long-term studies of NRT effects do not yet exist and would be needed to definitively answer the question about NRT efficacy and cancer risk and some decision making will need to be made based on limited human data and experimental studies. The overall NRT safety question is complex and requires consideration of three contexts and comparator groups (long-term NRT/abstinence vs. smoking, long-term intermittent NRT/ reduced smoking vs. smoking, and long-term NRT/abstinence vs. abstinence without long-term NRT). Although the data on these issues are insufficient, the first comparison seems intuitive and may be compelling enough to allow the FDA to approve a long-term indication for NRT. An important public health goal is to help smokers and their health care providers understand the implications of potential long-term NRT risks in the context of its potential benefits and the far greater risks of continued smoking. Cancer Prev Res; 4(11); 1719-23. Ó2011 AACR.The efficacy and safety of short-term nicotine replacement therapy (NRT) for fostering long-term smoking cessation is well established, and up to 12 weeks of therapy is approved by the U.S. Food and Drug Administration (FDA; refs. 1-4). A meta-analysis indicates that there are measurable benefits in studies of 12 to 18 months of continued NRT use for relapse prevention (5), and other studies also indicate that this use is cost effective (6). An important question of considerable interest that remains today, however, is whether NRT can be recommended for long-term use, even years, to continue to promote smoking abstinence. The answer to this question requires both an efficacy and safety assessment. In this context, NRT conceptually has substantial benefits compared with long-term smoking but also, as explained later and addressed in this issue of the journal, laboratory studies suggest a potential for nicotine to foster the development of cancer.The premise of long-term NRT use is that it would prevent smoking relapse, and the risks would be limited to maintaining nicotine addiction, but without the adverse consequences of continued smoking, such as increased lung cancer risk. Like the consideration of other long-term medications, on face value it is a simple risk-benefits equation. In actuality, however, this question is not simple to answer because the risk can be considered in 3 different contexts and comparator groups namely: (i) what is the risk o...

Nicotine, Carcinogen, and Toxin Exposure in Long-Term E-Cigarette and Nicotine Replacement Therapy Users

“…The lower carcinogen and toxicant levels associated with NRT-only and EC-only use in this study confirm the known low risk for long-term NRT product use (57). They also underscore the translation of greatly reduced concentrations of some carcinogens and toxicants from e-liquids and aerosol (4, 6, 58) to body-level exposure, contrary to worries that long-term EC use would result in substantial harmful exposure (59).…”

Electronic cigarette use and risk perception in a Stop Smoking Service in England

“…Users mostly viewed e-cigarettes as a short-term smoking cessation tool (73.9%), whereby they presumably intended on weaning themselves off the product within a limited time. Short-term nicotine replacement therapy is established as an effective and safe approach to fostering smoking cessation (Shields, 2011). Contrary to this, a proportion of participants did view e-cigarettes as a product which they intended to use long-term (20.3%).…”

Staying a Step Ahead of Cancer

“…Cigarette smoking leads to lung cancer since smoking exposes the individual to multiple DNA-damaging carcinogens and mutagens that result in mutations in critical genes that control cellular growth (Gonzalez et al 2011, Hymowitz 2011, Lam and Minna 2011, Pesch et al 2011, Proctor et al 2011, Shields 2011. Moreover, smokers are exposed to multiple tumor promoting substances and inflammatory agents that exacerbate the process.…”