Key Findings
Pancreatic cancer (PC) is increasingly more common in developed regions and approximately 104,000 new cases were diagnosed in Europe in 2012. The use of biomarkers may offer a valid estimation of the contribution of fatty acids (FAs) to the etiology of PC. In this study, a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort was used to estimate the association of specific plasma phospholipid levels of relevant FAs and PC risk. In addition, we used the desaturation index as an indicator of endogenous MUFA synthesis to investigate the association between fat metabolism and pancreatic carcinogenesis. Significantly reduced risk of PC was found among subjects with higher levels of saturated heptadecanoic acid (17:0) and pentadecanoic acid (15:0), as well as with cis n-3 polyunsaturated α-linolenic acid (18:3n-3) and docosapentaenoic acid (22:5n-3). In sex-stratified analysis, industrial TFAs were positively associated with PC risk among men, while conjugated linoleic acids conferred a significantly reduced risk among women. There was a significantly higher risk of PC associated with the long-chain n-6/n-3 PUFA ratio among smokers. Strengths of this study are the prospective and multi-center study design, the ability to distinguish various FA isomers, the relatively long follow-up time and the detailed information on lifestyle factors. In conclusion, this study based on biomarkers of FA exposure provides support for a possible inverse relationship between specific FA isomers present in dairy products, seeds and marine foods on the development of PC.
ABSTRACT
There are both limited and conflicting data on the role of dietary fat and specific fatty acids in the development of pancreatic cancer. In this study, we investigated the association between plasma phospholipid fatty acids and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The fatty acid composition was measured by gas chromatography in plasma samples collected at recruitment from 375 incident pancreatic cancer cases and 375 matched controls. Associations of specific fatty acids with pancreatic cancer risk were evaluated using multivariable conditional logistic regression models with adjustment for established pancreatic cancer risk factors. Statistically significant inverse associations were found between pancreatic cancer incidence and levels of heptadecanoic acid (ORT3-T1 [odds ratio for highest versus lowest tertile] =0.63; 95%CI[confidence interval]=0.41-0.98; P=0.036), n-3 polyunsaturated α-linolenic acid (ORT3-T1 =0.60; 95%CI=0.39-0.92; P =0.02) and docosapentaenoic acid (ORT3-T1 =0.52; 95%CI=0.32-0.85; P=0.008). Industrial trans-fatty acids were positively associated with pancreatic cancer risk among men (ORT3-T1 =3.00; 95%CI=1.13-7.99; P=0.029), while conjugated linoleic acids were inversely related to pancreatic cancer among women only (ORT3-T1 =0.37; 95%CI=0.17-0.81; P=0.008). Among current smokers, the long-chain n-6/n-3 polyunsaturated fatty acids ratio was positively associated with pancreatic cancer risk (ORT3-T1 =3.40; 95%CI=1.39-8.34; P=0.007). Results were robust to a range of sensitivity analyses. Our findings suggest that higher circulating levels of saturated fatty acids with an odd number of carbon atoms and n-3 polyunsaturated fatty acids may be related to lower risk of pancreatic cancer. The influence of some fatty acids on the development of pancreatic cancer may be sex-specific and modulated by smoking.
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