Molecular Markers Identify Oral Cancer Risk

A group of molecular markers have been identified that can help clinicians determine which patients with low-grade oral premalignant lesions are at high risk for progression to oral cancer.

A method based on differences in DNA has been developed from patients with oral premalignant lesions, where progression to cancer was known to have subsequently occurred, enabling the grouping of patients into low-risk or high-risk categories.

Scientists at the British Columbia (BC) Cancer Agency (Vancouver, Canadaa) analyzed samples from 296 patients with mild or moderate oral dysplasia. The samples had been identified and followed over years by the BC Oral Biopsy Service, which receives biopsies from dentists and ear nose and throat (ENT) surgeons across the province. Areas of dysplasia were microdissected for microsatellite analysis. Two additional DNA molecular risk markers called loss of heterozygosity were added to the analysis in an attempt to better differentiate patients' risks.

The investigators used the disease samples from the prospective study, and categorized patients into low-, intermediate- and high-risk. Patients classified as high-risk had an almost 23-fold increased risk for progression. Of patients categorized as low-risk, only 3.1% had disease that progressed to cancer within five years. In contrast, intermediate-risk patients had a 16.3% five-year progression rate and high-risk patients had a 63.1% five-year progression rate.

Miriam Rosin, PhD, the senior author of the study, said, "That means that two out of every three high-risk cases are progressing. Identifying which early lesions are more likely to progress may give clinicians a chance to intervene in high-risk cases, and may help to prevent unnecessary treatment in low-risk cases." Oral cancers are a global public health problem with close to 300,000 new cases identified worldwide each year. Many of these cancers are preceded by premalignant lesions. Severe lesions are associated with a high progression risk and should be treated definitively. The study was published on August 21, 2012, in the journal Cancer Prevention Research.

Related Links:
British Columbia Cancer Agency