Patients with head and neck cancer who tested positive for human papillomavirus (HPV) had higher survival rates when radiation therapy was combined with the targeted therapy cetuximab, according to a study to be presented at the meeting of the American Society for Radiation Oncology (ASTRO), Oct. 31 through Nov. 4 in San Diego.
Previous research has found that patients testing HPV-positive in head and neck squamous cell carcinoma (HNSCC) have higher survival rates when treated with chemotherapy or radiation therapy. K.R. Unger, MD, of Georgetown University Hospital in Washington, DC, and colleagues sought to investigate whether cetuximab, in combination with radiation therapy, also was associated with improved survival rates in HPV-positive tumor patients.
The study treated twenty HNSCC HPV-positive patients, median age 63 years, with seven to eight weeks of radiation therapy (median dose 72.0 Gy) and 400 mg/m 2 load and 250 mg/m 2 weekly of cetuximab, with a median of seven cycles. Tumor sites included 12 oropharynx, five larynx, one oral cavity, one hypopharynx and one unknown site.
After a median follow-up of 14 months, four patients had died and 13 patients' tumors had progressed. The one-year progression free survival rate was 100 percent for patients with HPV-positive tumors and 31 percent for HPV-negative tumors. Two year progression-free survival rates were 60 percent for HPV-positive tumor-patients and 23 percent for HPV-negative patients.
Overall survival rates were also higher in HPV-positive tumor patients, but these findings were not statistically significant. The researchers did not observe statistically significant differences between overall survival or progression-free survival and tumor stage, tumor or nodal status, primary site or radiotherapy duration.
The authors noted that their findings that HPV-positive tumors demonstrated improved progression-free survival with radiation therapy and cetuximab were "consistent with previous reports that HPV-positive disease has a better prognosis irrespective of the treatment modality."