Toluidine Blue ID’s Oral Lesions Likely to Become Cancer

Toluidine blue, a metachromatic dye commonly used in the histology lab, seems to be useful for identification of future oral cancers, as discovered by a team of scientists from O’Canada:

According to a study published in the September 1 issue of Cancer Research, the scientists found that lesions that took up the dye known as toluidine blue were six times more likely to become oral cancers.
The team also discovered that the dye-staining lesions contained molecular alterations that are linked to high risk of oral cancers — even at early stages.
“In oral cavity lesions, tissue that stained positive with toluidine blue were more likely to advance to cancer than lesions that did not stain with the dye,” said Miriam Rosin, Ph.D., Director of the BC Cancer Agency’s British Columbia Oral Cancer Prevention Program and Professor, Simon Fraser University. Rosin is the senior author on the study, funded by the National Institute of Dental and Craniofacial Research, of the National Institutes of Health.
Toluidine blue is an accepted indicator of oral cancers, Rosin said. The current studies, however, demonstrate that the dye accurately predicts which pre-malignant lesions are likely to advance toward disease. Those lesions appear as white or, less frequently, red patches.
“The vast majority of those white patches are often from minor inflammation and irritation,” Rosin said. Some, however, are inclined to become cancer-and are the ones targeted by this simple imaging technology.
In the study of 100 patients, Rosin and her colleagues learned that toluidine blue-stained lesions became squamous cell carcinomas more quickly than lesions that did not stain. The scientists also determined that dye-stained oral lesions were more likely to be aberrant not only at the gross tissue level but at the molecular genetic level as well. Toluidine blue was applied to lesions in the mouths of patients during dental visits to determine the value of the stain for imaging precancerous lesions.
“Oral premalignant lesions that stained with toluidine blue consistently contained loss of chromosomal genetic information,” Rosin said.

Press release from the American Association for Cancer Research…