HPV Status Predicts Survival, Progression Of Oral Cancer
Patients with certain oral cancers that contain the human papillomavirus (HPV) have better outcomes than similar patients with tumors that lack the virus, according to the largest and most definitive study of its kind to date.
The research involved 323 patients with stage III or IV oropharyngeal cancer (cancers of the upper throat) who were part of a Radiation Therapy Oncology Group clinical trial. Of these patients, 206 had HPV-positive tumors and 117 had HPV-negative tumors.
“Our findings show that HPV status is as strong a predictor of outcome as cancer stage for patients with oropharyngeal cancers, even after considering other factors such as age and smoking history,” said lead author Dr. Maura Gillison, a medical oncologist and head and neck cancer specialist at the Ohio State University Comprehensive Cancer Center-James Cancer Hospital and Solove Research Institute. “We’re still not entirely sure why this is, but these data provide further evidence that HPV-positive oropharyngeal cancer is a distinct disease entity.”
Gillison will present the findings at the 2009 annual meeting of the American Society of Clinical Oncology in Orlando, Florida.
Previous smaller studies by Gillison and others have suggested that oropharyngeal cancer patients with HPV-positive tumors fare better than their HPV-negative counterparts. But patients with HPV-positive oropharyngeal cancer tend to be younger and have smaller tumors at diagnosis, and they are less likely to smoke than HPV-negative patients. This is the first study large enough to consider HPV together with these other factors in patients who received the same therapy in a large clinical trial.
Gillison and her colleagues compared the patients for overall survival and for progression-free survival, the time it took for cancer to again progress.
After a median follow-up of 4.5 years and controlling for possible confounding factors such as therapy and smoking status, 88 percent of the HPV-positive patients were still alive after two years compared with 66 percent of HPV-negative patients.
Progression-free survival for the groups was 72 percent and 50 percent, respectively, after two years. The incidence of second primary cancers among HPV-positive patients was less than half that of HPV-negative patients: 4 percent versus 11 percent.
The findings suggest that patients with HPV-positive tumors have less than half the chance of dying from their cancers in five-years compared to those with HPV-negative tumors.
Gillison noted that the association between HPV and head and neck cancers is already changing the way clinical trials are designed, with investigators stratifying patients by HPV status. Gillison and investigators in national clinical trial groups are now designing therapeutic trials specific for HPV-positive or HPV-negative patients because of the differences in treatment response in the two groups. Studies are also being designed to assess the effectiveness of HPV vaccines for the prevention of these cancers.