TORONTO -- November 3, 2009 -- Researchers have confirmed that patients with oropharyngeal squamous cell cancer harbour a common type of human papilloma virus (HPV16), but also that such cancers are very sensitive to radiation.
For some patients, this may mean successful treatment with radiation alone and avoiding the side effects of chemotherapy. The findings are published in the November 2 issue of the Journal of Clinical Oncology.
"This represents the power of personalised medicine," said principal investigator Fei-Fei Liu, Division of Applied Molecular Oncology, Ontario Cancer Institute, Toronto, Ontario. "By using a relatively simple molecular test to evaluate the tumour, we can customise the treatment plan, produce an excellent outcome, and maintain the patient's quality of life."
Dr. Liu and colleagues discovered that patients whose tumours tested positive for HPV16 had a much better survival, compared with patients whose tumours did not harbour HPV16. This HPV effect was independent of treatment (radiation alone, or radiation plus chemotherapy), suggesting that some HPV16 patients could be treated with radiation only.
The study's finding is important because this particular type of cancer is increasing -- up more than 10% in the past 20 years. The jump is likely attributed to the spread of HPV16 through sexual activity, compared with a 20% decline in other similar head-and-neck cancers over the same period because fewer people are now smoking.
"Of course the goal is to prevent HPV infection in the first place, but for individuals who need treatment now, it's a major step to know that we could provide options so that some of our patients could be spared the often-difficult side effects of chemotherapy," said Dr. Liu.
The research team analysed tumour biopsies of 111 patients comparing clinical diagnosis, treatment plans, and outcomes. They found HPV16 in 60% of the samples, and determined that these patients experienced a much better survival, compared to the HPV-negative patients.
SOURCE: University Health Network