No association between educational level and pancreatic cancer incidence in the European Prospective Investigation into Cancer and Nutrition
van Boeckel PGA., Boshuizen HC., Siersema PD., Vrieling A., Kunst AE., Ye W., Sund M., Michaud DS., Gallo V., Spencer EA., Trichopoulou A., Benetou V., Orfanos P., Cirera L., Duell EJ., Rohrmann S., Hemann S., Masala G., Manjer J., Mattiello A., Lindkvist B., Sánchez MJ., Pala V., Peeters PHM., Braaten T., Tjonneland A., Dalton SO., Larranaga N., Dorronsoro M., Overvad K., Illner AK., Ardanaz E., Marron M., Straif K., Riboli E., Bueno-de-Mesquita B.
Introduction: Until now, studies examining the relationship between socioeconomic status and pancreatic cancer incidence have been inconclusive. Aim: To prospectively investigate to what extent pancreatic cancer incidence varies according to educational level within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Methods: In the EPIC study, socioeconomic status at baseline was measured using the highest level of education attained. Hazard ratios by educational level and a summary index, the relative indices of inequality (RII), were estimated using Cox regression models stratified by age, gender, and center and adjusted for known risk factors. In addition, we conducted separate analyses by age, gender and geographical region. Results: Within the source population of 407, 944 individuals at baseline, 490 first incident primary pancreatic adenocarcinoma cases were identified in 9 European countries. The crude difference in risk of pancreatic cancer according to level of education was small and not statistically significant (RII=1.14, 95% CI 0.80-1.62). Adjustment for known risk factors reduced the inequality estimates to only a small extent. In addition, no statistically significant associations were observed for age groups (adjusted RII≤ 60 years=0.85, 95% CI 0.44-1.64, adjusted RII>60 years=1.18, 95% CI 0.73-1.90), gender (adjusted RIImale=1.20, 95% CI 0.68-2.10, adjusted RIIfemale=0.96, 95% CI 0.56-1.62) or geographical region (adjusted RIINorthern Europe=1.14, 95% CI 0.81-1.61, adjusted RIIMiddle Europe=1.72, 95% CI 0.93-3.19, adjusted RIISouthern Europe=0.75, 95% CI 0.32-1.80). Conclusion: Despite large educational inequalities in many risk factors within the EPIC study, we found no evidence for an association between educational level and the risk of developing pancreatic cancer in this European cohort. © 2010 Elsevier Ltd.