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The International Agency for Research on Cancer (IARC) categorized cadmium as known human carcinogens, i.e., category I compound. Cadmium has been hypothesized as cause for pancreatic cancer. In Louisiana, the high rates of pancreatic cancer match the high levels of cadmium exposure. Rice grown in cadmium-contaminated areas in Louisiana has up to three times the level of cadmium compared to imported rice. A previous case-control study in Louisiana showed a significantly increased risk for pancreatic cancer associated with rice consumption with a dose-response relationship.
 A pilot case-control study was conducted in the Acadiana region of south Louisiana to examine the relationship between environmental factors and pancreatic cancer. Seventy-one pancreatic cancer cases and 158 sex, race, and age-group matched population controls were recruited in the study. A urine sample was collected from each of the participants along with structured interview regarding occupation and residential history, life style and dietary factors, sociodemographic factors, and DNA. No proxy interviews were accepted in this study. Urine samples were analyzed for cadmium level as a biomarker of long term cadmium exposure. Primers that hybridize to the 5'- region of exon 4 of the glutathione S-transferase, mu 1(GSTM1) gene was used to detect deletion of this gene.
 This study found that average urinary cadmium level adjusted for urinary creatinine was significantly higher (p < 0.01) among pancreatic cancer cases compared to healthy controls (1.62 ug Cd/g Creatinine vs 1.01[[Unsupported Character - &#61472;]] ug Cd/g Creatinine, respectively). Multivariate regression models were used to examine the association between pancreatic cancer and urinary cadmium adjusting for age, race, gender, cigarette smoking. Urinary cadmium was marginally significantly associated with pancreatic cancer when all subjects combined (OR = 1.20, 95% CI = 0.98, 1.47). However, no association was found among subjects with GSTM1 gene (OR=1.08, 95%CI = 0.86, 1.36). On the other hand, higher urinary cadmium level was significantly associated with elevated odds of pancreatic cancer (OR = 1.51, 95%CI = 1.07, 2.12).
 The phase II glutathione S-transferases (GSTs) are a family of enzymes responsible for metabolism of a broad range of xenobiotics and carcinogens. Allelic variants of GSTs that have impaired detoxification function may increase the rate of genetic damage and thereby increase the susceptibility to cancer. Cadmium has an extremely long biological half-life, ranging from 10 to 30 years in the human body with an average of 15 years. The body has no mechanism for excreting excessive amounts of cadmium so cadmium accumulates in tissues. The findings of this study suggest that higher excretory cadmium level is significantly associated with increased risk of pancreatic cancer among GSTM1 null subjects but not GSTM1 positive ones. GST may be involved in the detoxification of cadmium.

99th AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA