Association between Cigar or Pipe Smoking and Cancer risk in Men: A Pooled Analysis of Five Cohort Studies.

Use of non-cigarette tobacco products such as cigars and pipe has been increasing even though these products entail exposure to similar carcinogens to those in cigarettes. More research is needed to explore the risk of these products to guide cancer prevention efforts.

To measure the association between cigars and/or pipe smoking, and cancer incidence in men, we performed meta-analyses of data from five prospective cohorts. Cox regression was used to evaluate the association between different aspects of cigars and pipe smoking and risk of each smoking-related cancer (head & neck, esophagus, lung, stomach, liver, pancreas, kidney, bladder) for each study. Adjusted hazard ratios were combined using random-effects models.

Cigars and/or pipe smokers were at increased risk for head & neck (HR 1.51; 95% CI 1.22 to 1.87), lung (HR 2.04; 95% CI 1.68 to 2.47) and liver cancers (HR 1.56; 95% CI 1.08 to 2.26). Ever-smokers of cigars and/or pipe had an increased risk of developing a smoking-related cancer when compared to never smokers of any tobacco product (overall HR 1.07; 95% CI 1.03 to 1.12). The risk for smoking-related cancers was also increased in mixed smokers who smoked cigars or pipe as well as cigarettes, even when they were smoking predominantly pipe or cigars.

This pooled analysis highlights the increased risk for smoking-related cancers, particularly for lung and head & neck cancers in exclusive and predominant smokers (former and current) of cigars and pipe. Tobacco prevention efforts should include these products in addition to cigarettes.

Cancer prevention research (Philadelphia, Pa.). 2017 Sep 28 [Epub ahead of print]

Jyoti Malhotra, Claire Borron, Neal D Freedman, Christian C Abnet, Piet A van den Brandt, Emily White, Roger L Milne, Graham G Giles, Paolo Boffetta

Medical Oncology, Rutgers Cancer Institute of New Jersey ., Icahn School of Medicine at Mount Sinai., Division of Epidemiology & Genetics, National Cancer Institute., Division of Cancer Epidemiology and Genetics, National Cancer Institute., Department of Epidemiology, GROW - School for Oncology and Developmental Biology, Maastricht University., Cancer Prevention Program, Fred Hutchinson Cancer Research Center., Cancer Council Victoria, University of Melbourne.