Prediagnostic whole-blood cadmium and molybdenum associated with pancreatic cancer in an American cohort

Abstract

Environmental exposures to elements such as cadmium might be contributing to the increasing incidence of pancreatic cancer. Few prospective studies have examined the association between trace elements and pancreatic ductal adenocarcinoma (PDAC). We conducted a nested case-control study in participants aged 55-74 years at baseline from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial cohort to examine the association between 12 trace elements measured in prediagnostic whole-blood samples and PDAC. From May 1998 through December 2014, 318 incident PDAC cases were identified during follow-up to 16.7 years. Of 636 control participants, 2 who were alive when each case patient was diagnosed were selected and matched by age (±5 years), sex, calendar date of blood sample collection (2-month blocks), and race and ethnic group. We used multivariable adjusted conditional logistic regression to calculate odds ratios (ORs) and 95% CIs. Cadmium and molybdenum were associated with PDAC (highest compared with lowest quintile: for cadmium, OR = 1.81 [95% CI, 01.12-2.95], P = .03 for trend; for molybdenum, OR = 0.50 [95% CI, 0.32-0.80], P = .02 for trend). The inverse molybdenum association was only observed among ever smokers (OR = 0.31 [95% CI, 0.17-0.58]; P = .003 for trend, P = .03 for interaction) with no association in never smokers. Lead, arsenic, and other trace elements were not associated with PDAC. Our results support that an increasing prediagnostic whole-blood level of cadmium is associated with increased PDAS risk, whereas that for molybdenum reduces PDAC risk.

Keywords: cadmium; molybdenum; pancreatic cancer; prospective epidemiologic study; trace elements.