New method to test for oral cancer

Oral cancers and precancerous mouth lesions are considered especially difficult to diagnose early and accurately. But a team of researchers, led by a clinician scientist at the Case Western Reserve University (CWRU) School of Dental Medicine in Ohio in the United States, has discovered a non-invasive, low-cost test to detect oral cancer, monitor precancerous lesions and determine when a biopsy is warranted.

Their findings, published the journal Cell Reports Medicine, are based on a scoring system linked to the levels of two proteins in cells brushed from suspicious oral lesions of patients at dental clinics or the ear, nose and throat department at university hospitals (UH).

One of the proteins (hBD-3) is expressed at high levels in early-stage oral cancer, while the second (hBD-2) is low or unchanged. The ratio of hBD-3 to hBD-2 in the lesion site generates a score, called the beta defensin index (BDI). A score above a predetermined threshold implies cancer; anything below does not.

“When we first discovered hBD-3, we saw it acted as a ‘good guy’, involved in wound-healing and killing microbes,” said Aaron Weinberg, chair of the Department of Biological Sciences at the CWR School of Dental Medicine and the study’s lead researcher.

He explained that when they found hBD-3 was regulated the same way certain cells grow uncontrollably, they started studying it in the context of oral cancer: “We found it was not only promoting tumor growth but it was overexpressed in the early stages of the disease, while another member, hBD-2, wasn’t changing. This difference in levels of expression of the two proteins compared to the opposite side in the same patient led us to examine the BDI’s ability to distinguish cancer from benign lesions”.