Elevated lung cancer risk shortly after smoking cessation: Is it due to a reduction of endotoxin exposure?

Lange, J.H.; Mastrangelo, G.; Fadda, E.; Priolo, G.; Montemurro, D.; Buja, A.; Grange, J.M.

doi:10.1016/j.mehy.2005.02.043

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Volume 65, Issue 3 , Pages 534-541, 2005

Elevated lung cancer risk shortly after smoking cessation: Is it due to a reduction of endotoxin exposure?

J.H. Lange
- Envirosafe Training and Consultants, P.O. Box 114022, Pittsburgh, PA 15239, USA
G. Mastrangelo
- Department of Environmental Medicine and Public Health, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
- Corresponding author. Tel.: +39 049 821 2543; fax: +30 049 821 2542
E. Fadda
- Department of Environmental Medicine and Public Health, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
G. Priolo
- Department of Environmental Medicine and Public Health, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
D. Montemurro
- Department of Clinical and Experimental Medicine, University of Padova, Italy
A. Buja
- Department of Environmental Medicine and Public Health, University of Padova, Via Giustiniani 2, 35128 Padova, Italy
J.M. Grange
- Centre for Infectious Diseases and International Health, Royal Free and University College Medical School, Windeyer Institute for Medical Sciences, 46 Cleveland Street, London W1T 4JF, UK

Received 23 February 2005; accepted 24 February 2005. published online 23 May 2005.

Summary

Several reports indicate that the risk of lung cancer increases slightly for a short period of time after cessation of smoking while the risk of adverse cardiovascular events drops immediately. Recent studies on subjects occupationally exposed to organic dust-containing endotoxin have revealed lower than expected rates of lung cancer. There is experimental evidence that stimulation of the immune system by endotoxin has a protective effect against cancer. Tobacco smoke has been shown to contain high levels of endotoxin. We therefore postulate that cessation of smoking eliminates the protective effect of endotoxin. Any benefit conferred by endotoxin does not, however, justify smoking. As the inverse relationship between exposure to endotoxin and the risk of lung cancer is a strong one, endotoxin-like substances could form the basis of vaccination strategies.