Table 14.2 Risk factors for pancreatic cancer, by direction of association and strength of evidence
| Increases risk | Decreases risk |
Convincing or probable | Tobacco smoking1 | |
| Smokeless tobacco1,2 | |
| Alcohol1,3,4 | |
| Chronic pancreatitis5 | |
| Diabetes6,7 | |
| Greater body fatness/abdominal fatness8,9 | |
| Height/tallness10 | |
| Occupational exposure to styrene11 | |
| Family history of pancreatic cancer12,13,14 | |
Possible | Involuntary (passive) smoking15,16 | Metformin19 |
| Insulin resistance/metabolic syndrome17 | Physical activity20 |
| Red meat10,18 | Folate10,21 |
| | Allergic conditions and/or atopy22,23 |
1 Secretan et al., 2009; 2 chewing tobacco or snuff; 3 Michaud et al., 2010; 4 Lucenteforte et al., 2011; 5 Raimondi et al., 2010; 6 Ben et al., 2011; 7 Li et al., 2011b; 8 Jiao et al., 2010; 9 Arslan et al., 2010; 10 World Cancer Research Fund / American Institute for Cancer Research, 2007; 11 National Toxicology Program, 2008; 12 one or more first degree relatives(s) with cancer of the pancreas; 13 Maisonneuve and Lowenfels, 2010; 14 Jacobs et al., 2010; 15 exposure in childhood and/or in adulthood at home or work; 16 Vrieling et al., 2010; 17 Rosato et al., 2011; 18 beef, pork and lamb; 19 Decensi et al., 2010; 20 O’Rorke et al., 2010; 21 found in green leafy vegetables and beans, peas and lentils; 22 including eczema, hay fever and rhinitis; 23 Gandini et al., 2005c |
Tobacco smoking is causally related to pancreatic cancer (Table 14.2) and accounts for 20-25% of cases (Maisonneuve & Lowenfels, 2010). Smokers of cigarettes, cigars and pipes are all at increased risk; risk increases with duration of smoking and cumulative smoking dose, and decreases to background levels 15 years after smoking cessation (Lynch et al., 2009). Use of smokeless tobacco is also a causal factor and there are suggestions that individuals exposed to environmental tobacco smoke either in childhood, or at home or work as adults, have increased risk of pancreatic cancer. Alcohol is also causally related to pancreatic cancer although the association appears to be restricted to individuals with high alcohol intake, and may be limited to men.
As regards medical conditions, around 5% of patients with long-term inflammation of the pancreas (chronic pancreatitis) are likely to develop pancreatic cancer over a 20 year period. Diabetics have increased risk, especially insulin users, but some uncertainties remain regarding the association (Magruder et al., 2011). In a few studies, insulin resistance and metabolic syndrome have also been linked to elevated pancreatic cancer risk, while use of metformin as a treatment for diabetes has been associated with reduced risk. Inverse associations have been reported between allergic conditions and atopy and pancreatic cancer risk.
Taller adults have increased risk, but height per se is unlikely to affect risk; it is most probably a marker for a risk factor related to linear growth in childhood. Risk of pancreatic cancer increases with increasing body fatness, by 6% for men and 12% for women per 5kg/m2 increase in body mass index. In addition, most studies which have examined measures of abdominal fatness have reported positive findings. Some other lifestyle-related factors have been linked to pancreatic cancer (e.g. physical activity, aspects of diet), but the evidence regarding these remains somewhat uncertain.
An estimated 5-10% of pancreatic cancers arise as a result of genetic syndromes. One affected first degree relative confers a 75% increased risk.
Printer-friendly version
