Color of oral tissue may reflect colon cancer

By Karla Gale

NEW YORK (Reuters Health) - Abnormalities in "oral mucosal light reflectance" are associated with an inherited form of colon cancer called hereditary non-polyposis colorectal cancer (HNPCC) and may represent a new tool for population screening, investigators from Italy report.

The oral mucosa of individuals affected by HNPCC has a "very particular hue," Dr. Claudio De Felice explained in comments to Reuters Health.

De Felice, from Azienda Ospedaliera Universitaria Senese in Siena, and others photographed and assessed the oral tissue of 20 members of six genetically unrelated HNPCC families and 30 age- and gender-matched healthy control subjects.

Compared with the controls, the oral mucosa of all subjects with HNPCC exhibited significantly lower reflectance values in the 590-700 nm wavelength range. The specificity and sensitivity of a reflectance cutoff value of less than 47.9 percent at 700 nm yielded a specificity and sensitivity of 100 percent.

De Felice believes analysis of color should be an important tool in clinical medicine, because it is associated with the physical state and chemical composition of tissue. However, up until now, "it has been highly under-evaluated."

The investigators attribute the aberrant optical properties of the mucosa to abnormalities in the network of material that surrounds cells, known as the extracellular matrix.

"Extracellular matrix appears to be an important architectural underlying structure for a correct microvascular network development," De Felice noted. "Earlier work by our group has shown a significantly aberrant microvascular network demonstrable in HNPCC patients and families."

"Underlying extracellular matrix abnormalities may play a role in other cancers as well, but that remains to be elucidated," the investigator added. He believes "the reflectance values may vary according to the kind of cancer evaluated."

SOURCE: Gut, October 2006.