Childhood Body Mass Index and Risk of Adult Pancreatic Cancer

Background: Excess weight in adulthood is one of the few modifiable risk factors for pancreatic cancer, and height has associations as well. This leads to the question of whether body weight and height in childhood are associated with adult pancreatic cancer. Objective: The aim of the study was to examine if childhood body mass index (BMI; kg/m(2)) and height are associated with pancreatic cancer in adulthood. Methods: We linked 293,208 children born from 1930 to 1982 in the Copenhagen School Health Records Register who had measured values of weights and heights at ages 7–13 y with the Danish Cancer Registry to identify incident pancreatic cancer cases from 1968 to 2012. HRs and 95% CIs were estimated by using Cox proportional hazards regressions. Results: During 8,207,015 person-years of follow-up, 1268 pancreatic cancer cases were diagnosed. Childhood BMI z scores at ages 7–13 y were positively and significantly associated with pancreatic cancer in men and women <70 y of age; ≥70 y of age, the associations diminished. The HRs of pancreatic cancer were 1.13 (95% CI: 1.05, 1.21) and 1.18 (95% CI: 1.09, 1.27) according to BMI z score at ages 7 and 13 y, respectively. A BMI z score of ≥1.5 at ages 7, 10, and 13 y was positively and significantly associated with pancreatic cancer; however, the effect did not differ from having a BMI z score ≥1.5 at only one of these ages. Positive, albeit nonsignificant, associations were identified with height. Conclusions: BMI at all ages from 7 to 13 y was positively and linearly associated with adult pancreatic cancer: the higher the BMI, the higher the risk. Excess childhood BMI may be indicative of processes initiated early in life that lead to this cancer. The prevention of childhood adiposity may decrease the burden of pancreatic cancer in adults.