Abstract 1780: Differences in pancreatic cancer incidence across five racial/ethnic populations in the Multiethnic Cohort
Authors: Setiawan Veronica Wendy , Haiman Christopher A. , Stram Daniel O. , Pandol Stephen J. , Wilkens Lynne R. , Le Marchand Loic , Monroe Kristine R. 
Published: July 2016

Background: The pancreatic cancer incidence is steadily increasing and the death-to-incidence ratio approaches one. While disparity in pancreatic cancer incidence between US blacks and whites has been observed, no study has been conducted to examine disparity in other populations. We examined racial/ethnic differences in pancreatic cancer incidence and assessed the extent to which known risk factors for pancreatic cancer account for differences in risk among African Americans, Native Hawaiians, Japanese Americans, Latinos and whites in the Multiethnic Cohort Study.

Methods: During a 16.2 year follow up period, 1,415 incident pancreatic cancer cases were identified among 183,269 at risk participants. Data on risk factors were obtained from the baseline questionnaire (1993-1996). Cox regression was used to calculate the age- and sex-adjusted relative risks (RRs) and 95% confidence intervals (CIs) for pancreatic cancer associated with risk factors and race/ethnicity.

Results: Current smoking status (RR&lt;20 pack-years = 1.40; 95% CI: 1.15, 1.71; RR≥20 pack-years = 1.72; 95% CI: 1.42, 2.09, P trend&lt;0.0001), obesity (BMI ≥30 kg/m2) (RR = 1.26; 95% CI: 1.08, 1.47), history of diabetes (RR = 1.38; 95% CI: 1.18, 1.60), family history of pancreatic cancer (RR = 1.91; 95% CI: 1.44, 2.54), and intake of red meat (RR highest vs. lowest quartile = 1.26; 95% CI: 1.08, 1.48, P trend = 0.025) were associated with increased risk of pancreatic cancer. The RRs for pancreatic cancer (vs. whites) were 1.76 (95% CI: 1.42, 2.18) for Native Hawaiians, 1.34 (95% CI: 1.13, 1.58) for African Americans, 1.28 (95% CI: 1.11, 1.48) for Japanese Americans, and 0.93 (95% CI: 0.79, 1.11) for Latinos. After further adjustment for the risk factors above, the RRs were 1.56 (95% CI: 1.26, 1.95) for Native Hawaiians, 1.20 (95% CI: 1.01, 1.43) for African Americans, 1.29 (95% CI: 1.10, 1.50) for Japanese Americans, and 0.87 (95% CI: 0.73, 1.04) for Latinos.

Conclusions: In the MEC, Native Hawaiians were at the highest risk of developing pancreatic cancer, followed by African Americans, Japanese Americans, whites, and Latinos. Interethnic differences in pancreatic cancer risk do not appear to be explained by differences in the distribution of known risk factors. The greater risks in Native Hawaiians and Japanese Americans compared to whites are new important findings and elucidating the causes of these high rates may improve our understanding of the disease.

Citation Format: Veronica Wendy Setiawan, Christopher A. Haiman, Daniel O. Stram, Stephen J. Pandol, Lynne R. Wilkens, Loic Le Marchand, Kristine R. Monroe. Differences in pancreatic cancer incidence across five racial/ethnic populations in the Multiethnic Cohort. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1780.