Adolescent obesity linked to increased risk for pancreatic cancer

Obesity during adolescence appeared associated with a fourfold increased risk for pancreatic cancer later in life, according to an analysis of 1.7 million Israeli Jewish men and women.

Men who were overweight or at the higher end of the normal BMI range also appeared at greater risk for pancreatic cancer risk in a graded manner.

“BMI at age 17 years was significantly and positively associated with pancreatic cancer in early adulthood among both men and women,” Zohor Levi, MD, MHA, researcher in the gastroenterology department at Rabin Medical Center in Petah Tikva, Israel, and colleagues wrote.

Levi and colleagues analyzed 1,087,385 Israeli Jewish men and 707,212 Jewish women who underwent physical exams between ages 16 to 19 years to determine their fitness for military service. The men and women were evaluated between 1967 and 2002 and had at least 10 years of follow-up.

Investigators used the Israeli National Cancer Registry to assess pancreatic cancer incidence.

Over a median 23.3 years of follow-up, researchers identified 551 cases of pancreatic cancer, 423 of which occurred among men.

Median age at diagnosis was 51 years (interquartile range, 44-55) and did not differ among BMI categories.

Compared with normal weight — defined as the 5th to 85th percentiles — obesity (95th percentile) was associated with a higher risk for pancreatic cancer among men (HR = 3.67; 95% CI, 2.52-5.34) and women (HR = 4.07; 95% CI, 1.78-9.29).

Compared with men who had low-normal BMI ( 5th to < 25th percentile), risk for pancreatic cancer appeared higher among men with high-normal BMI ( 75th percentile to < 85th percentile; HR = 1.49; 95% CI, 1.05-2.13) and those who were overweight (85th to 95th percentile; HR = 1.97; 95% CI, 1.39-2.8).

Being overweight or obese increased risk for pancreatic cancer among both men (HR = 1.68; 95% CI, 1.27-2.21) and women (HR = 3.89; 95% CI, 2.76-5.5).

Researchers calculated an estimated population-attributable fraction of pancreatic cancer attributable to overweight or obesity of 10.9% (95% CI, 6.1-15.6).

Levi and colleagues acknowledged limitations to their study, including a lack of data on weight change over time and waist-to-hip ratio or waist circumference, which are independently associated with increased risks for pancreatic cancer.

The researchers also did not have data on smoking status or family history of pancreatic cancer for members of the cohort.

“To our knowledge, this is the largest analysis to date of measures of adolescent obesity in association with the risk for pancreatic cancer,” Levi and colleagues wrote. “The large sample size enabled us to examine whether lesser degrees of obesity are associated with the risk [for] pancreatic cancer. ... On a practical note, [this study] further emphasizes the need for effective interventions to prevent childhood and adolescent obesity.” – by John DeRosier

Reference:

Levi Z, et al. Cancer. 2018;doi10.1002/cncr.31764.

Disclosure s : Israeli Cancer Research Fund and the Environment and Health Fund funded this study. The authors report no relevant financial disclosures.