October 5, 2009
DNA Test Could Target Treatments For Head And Neck Cancer
It is estimated that more than 7,000 people are diagnosed with head and neck cancer each year in the UK and approximately 3,500 cases result in death. These cancers include tumors of the mouth, lips, throat and voice-box, and some have been linked to the sexually transmitted infection, HPV-16. Scientists at Liverpool analyzed the DNA of more than 90 cancerous tissue samples to look for genes that indicated infection.
The team found that nearly two thirds of tonsil tumor samples showed evidence of the HPV-16 gene. It is thought that chemical alterations in the virus's DNA trigger the production of proteins that can alter the rate at which cells grow and repair. This strongly increases the possibility of subsequent cancer development. Recent studies have found, however, that patients who have the HPV infection when they are diagnosed with cancer, respond better to chemotherapy or radiation therapy than those that do not have the infection. The work will be presented at the National Cancer Research Institute's (NCRI) Cancer Conference in Birmingham today.
Mr Richard Shaw, from the School of Cancer Studies, explains: "Recent evidence demonstrates the possible involvement of HPV in the development of tonsil cancer, particularly in non-smokers. Interestingly, the treatment efficiency of chemotherapy and radiation, seems to differ between HPV positive and negative cases. We also need to find out why only a small percentage of people with this common infection develop this cancer. Our study, however, gives us a new lead towards a risk marker.
"It is thought that HPV interacts in the cell with genes controlling the chemical modification of DNA, which affects gene expression and tumor behavior. Our study shows that HPV may be a trigger of tonsil cancer, independent of the known common causes, such as smoking or drinking. The work also suggests that a DNA test to determine the activity of HPV, could be used to identify the most effective treatment for each individual patient.
"Liverpool has the largest centralized head and neck oncology practice in the UK and our data show a doubling in the rate of non-drinkers and non-smokers presenting with tonsil cancer. As head and neck cancer is one of the cornerstones of the new CR-UK Cancer Center in Liverpool, we are pleased to be making real progress in this area of research."
Researchers are now working to develop a clinical trial for a therapeutic HPV vaccine in head and neck cancer.
The study, supported by the Royal College of Surgeons, is presented at the NCRI Cancer Conference on Monday, 5 October.
On the Net: