Increased content of chromium and nickel in lung tissues from patients with bronchial carcinoma

Epidemiological studies have shown that occupational exposure to certain chromium and nickel compounds is followed by an increased lung cancer incidence. However, few data exist on the content of these metals in lung cancer patients in general. In the present study, central and peripheral lung tissue, bronchial tissue and hilar lymph nodes were collected from 20 patients with bronchial carcinoma and 21 control individuals, and the tissue concentration of chromium and nickel was measured by use of atomic absorption analysis. Increased levels of both metals were found in cancer patients as compared to controls. Lung tissue concentration of chromium was two-fold increased, while the bronchial wall content of nickel was three times the level in control individuals. Smokers showed a dose-related increase in the deposition of both chromium and nickel. Furthermore, in cancer patients an inverse relationship between smoking and the tissue level of chromium in regional lymph nodes was found, possibly indicating a depressive effect on pulmonary clearance mechanisms. Our results emphasize the possible role of small amounts of chromium and nickel as agents in bronchial carcinogenesis, unrelated to occupation and probably related to tobacco smoking.