Fluorescence visualization in oral neoplasia: shedding light on an old problem.

In this issue of Clinical Cancer Research , Poh et al. (1) show the effectiveness of a simple handheld light (blue excitation light at 400-460 nm) to clarify the true extent of tumor spread and, in turn, guide complete removal of oral cancers in the operating room. Optical changes (specifically, loss of fluorescence) in the epithelium in and around oral cancers was used to map the ‘‘field of cancerization.’’ Correlation with histopathologic features and specific genetic alterations indicate that fluorescence visualization is far superior to clinical judgment alone in gauging the size, extent, and distribution of the cancer field. Indeed, the field of optical changes seemed to more closely mirror the field of genetic changes than traditional light microscopy. This relatively simple approach of exposing subclinical alterations driven at the genomic level with lighting techniques and dyes such as toluidene blue could potentially find widespread practical application in operating rooms where definitive treatment of oral cancer relies on informed charting of the surgical boundaries.