Possible association between nickel and chromium and oral cancer: a case-control study in central Taiwan.

Oral cancer is one of the most common cancers in Taiwan. Changhua County, in central Taiwan, has an extremely high prevalence of oral cancer, along with a high concentration of metal-related industries and soil metal contamination. The aim of this study was to clarify the possible association between metals and oral cancer within this specific area. This study recruited 101 oral cancer patients and 104 controls from the Changhua Christian Hospital. All subjects completed a questionnaire that asked about demographic information; cigarette, alcohol, and betel quid use; and environmental and occupational exposure history. Blood samples were collected and tested for metal concentrations with inductively coupled plasma mass spectrometry. A multiple logistic regression model illustrated that oral cancer was significantly associated with the blood levels of nickel and chromium (both with P<0.0001) after controlling for potential confounders. This study suggested a potential role of these two metals in the mechanism of oral cancer development.