Purpose: Japanese Americans, Native Hawaiians and African Americans have a higher incidence of pancreatic cancer compared to non-Hispanic whites that cannot be explained by the rates of obesity or absolute body weight. While absolute body weight in adulthood is positively associated with pancreatic cancer risk, the effect of weight change throughout adulthood, particularly among a racially diverse population, is not well documented for this high-risk group. Methods: This population-based prospective cohort study included 155,308 participants enrolled in the Multiethnic Cohort from 1993-1996 (median follow-up = 20.2 years). We identified 1,328 participants diagnosed with incident primary invasive pancreatic cancer from the linked cohort data with the Hawaii and California SEER registries. Participants diagnosed with other cancers were excluded from the cohort analysis. Body weight at 21 years old and at baseline enrollment (age 45 or older) were assessed using a self-administered questionnaire at cohort entry. Multivariable Cox proportional hazards regression models were used to determine the association between weight change from age 21 to cohort entry and pancreatic cancer risk adjusting for known risk factors such as smoking status, physical activity, alcohol intake, family history of pancreatic cancer and other sociodemographic characteristics. Results: The mean age at cohort entry was 59.3 years (SD 8.9) and the largest proportion of the cohort were Japanese American (30.1%), White (25.0%), and Latino (21.8%), respectively. The mean weight change from age 21 to baseline age was 28 pounds (SD 26.7). We observed that increased risk of pancreatic cancer was associated with weight at age 21 (HR 1.06; 95% CI 1.03-1.09, per 10-pound increase; p-trend<0.001) and weight at baseline (1.03; 1.00-1.05, per 10-pound increase; p-tend=0.03). Weight gain through adulthood (per pound increase per year) was associated with 11% increased risk of pancreatic cancer (1.11; 1.03-1.20) after adjusting for known lifestyle and behavioral risk factors. There was a significant interaction (p=0.03) between weight gain per year in adulthood and race/ethnicity, where Japanese Americans and Latinos experienced a 36% (1.36; 95% CI 1.14-1.64; p-trend<0.001) and 33% (1.33; 95% CI 1.11-1.59; p-trend=0.02) increased risk of pancreatic cancer per pound gained per year, respectively. Conclusion: Our findings indicate that weight gain in adulthood has a significant and independent impact on pancreatic cancer risk and specifically among racial/ethnic minorities. This study underscores the importance of maintaining a stable weight through adulthood, regardless of weight at age 21, in order to lower the risk of pancreatic cancer.

Citation Format: Albert J Farias, Daniel O Stram, Songren Wang, Stephen J Pandol, Kristine R Monroe, V. Wendy Setiawan. Racial/ethnic disparities in weight, weight change in adulthood, and pancreatic cancer incidence: The Multiethnic Cohort [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C071.

©2020 American Association for Cancer Research.
2020
American Association for Cancer Research.