The association between blood cadmium levels and the risk of gastrointestinal cancer in Tabriz, northwest of Iran

Introduction Cancer is a major health problem worldwide. Gastrointestinal tract malignancy is one of the most common forms of cancer around the world. Occupational exposure to the heavy metals including cadmium was defined as one of the most important environmental risk factors involved in initiation of cancer. Cadmium, a toxic and non-essential heavy metal, was classified as group 1 carcinogen. Aim The aim of this study was to investigate the association between blood cadmium levels and the risk of gastrointestinal cancer in cancer patients. Material and methods This descriptive study was carried out on 111 gastrointestinal cancer patients as cases and 111 healthy people as controls from January to October 2013 in Tabriz, northwest of Iran. The protocol of this study is approved by the Ethics Committee in Tabriz University of Medical Science. Considering inclusion criteria, participants were selected randomly and a written informed consent was filled out for each patient. Demographic data were obtained by questionnaire. Blood samples (5 mL) were collected from each patient in fasting status and analyzed by graphite furnace atomic absorption spectrophotometer (GFAAS). Results and discussion Blood cadmium levels were significantly higher in cancer patients compared to healthy individuals (P = 0.037). The results of multivariate regression model did not show significant association between the concentrations of blood cadmium and the risk of gastrointestinal cancer: P = 0.137, OR = 1.15 (95% CI; 0.96–1.38). Conclusion Our data suggest that finding individuals with high blood cadmium level and then lowering this amount can be considered as important strategy to prevent gastrointestinal cancer.