Field cancerization in the aerodigestive tract--its etiology, manifestation, and significance.

Field cancerization of the mucous membranes of the aerodigestive tract frequently develops in response to tobacco and alcohol usage; it is characterized by a variety of premalignant and frankly malignant epithelial changes that may lead to the development of multiple primary cancers of the aerodigestive tract. Field cancerization can be demonstrated by supravital staining with toluidine blue or by electron microscopic study of random biopsies taken from apparently normal mucosa. Field cancerization should be taken into account in treatment planning of a patient with cancer so that all treatment options, including the use of radiation therapy, be kept open for as long as possible in the event that the patient may develop multiple primary tumors.