Association of environmental heavy metals exposure and lung cancer incidence and prognosis

Abstract

Background: An increased risk of lung cancer has been observed at exposure to certain environmental heavy metals. However, less is known about their carcinogenic potential to play a role in lung tumorigenesis and prognosis. Objectives: To verify the role of heavy metals in the development of lung cancer. Methods: A case-control study from normal population (n= 3345) was conducted to compare heavy metal contents between 50 lung cancer patients, 20 other malignancy patients, and 149 matched normal healthy people [table1] . The urine concentration of heavy metals, including vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), arsenic (As), strontium (Sr), cadmium (Cd), mercury (Hg) , thallium (Ti), and lead (Pb), were measured using by ICP-MS (Agilent 7500c). Results: People who lived nearby a naphtha cracking complex (10 – 20 km) had relative higher urine concentration of heavy metals, especially in Cr, Ni, Cd and Pb. Cd content in lung cancer patients were significantly higher than those with other malignancy and non-cancer controls, but V content was markedly lower in lung cancer [table2] . Cd content was significant higher in smokers [figure1] . Sr amount in patients with small cell lung cancer was relatively higher than those in non-small cell lung cancer. In addition, lung cancer patients with higher Cd and Cu level also had poor prognosis [figure2] . Conclusions: Accumulation of Cd could be an independent risk of lung cancer development. Highly exposure to Cd may result in poor prognosis of lung cancer patients.