Diet and other risk factors for cancer of the salivary glands:a population-based case-control study.

A population-based case-control study of cancer of the salivary glands, involving interviews of 41 incident cases and 414 controls, was conducted in Shanghai. After adjustment for other risk factors, occupational exposure to silica dust was linked to a 2.5-fold increased risk of salivary-gland cancer. The risk was also significantly elevated among individuals who reported ever using kerosene as cooking fuel or having a prior history of head X-ray examinations. Dietary analyses revealed a significant protective effect of consumption of dark-yellow vegetables or liver, with about 70% reduced risk of salivary-gland cancer among individuals in the highest intake group of these foods. Our findings are consistent with previous observations on a possible role of environmental exposure and radiation in the etiology of salivary-gland cancer, and suggest that dietary factors may contribute to the development of this malignancy.