RESUMO
OBJECTIVES: Trace elements are essential components of biological structures, but they can be toxic at concentrations beyond those necessary for their biological functions. METHODS: A study group of 30 patients with bladder cancer and a control group of 30 healthy volunteers were measured for trace elements using a graphite furnace atomic absorption spectrophotometer. RESULTS: Urinary zinc and selenium levels in patients were significantly (P < 0.05) higher than those in controls, but urinary copper, arsenic, and lead were not significantly different. CONCLUSION: This case-control study suggests that zinc and selenium concentrations are associated with the proliferation of bladder cancer cells because zinc and selenium are excreted in the urine of bladder cancer patients.