HPV Status Can Predict Outcome in Oropharyngeal Cancer
Adapted from the NCI Cancer Bulletin 1.
Patients with advanced forms of a cancer in the upper portion of their throat have better outcomes if their tumors are positive for the human papillomavirus (HPV), according to new data 2 from a phase III clinical trial presented at the 2009 annual meeting of the American Society of Clinical Oncology. (The findings were subsequently published in the July 1, 2010, issue of the New England Journal of Medicine; see the journal abstract 3.) Although other studies have suggested a link between HPV status and outcome in patients who have oropharyngeal cancer, these new data provide the most definitive evidence, said the study's leader, Maura Gillison, M.D., Ph.D., of Ohio State University, at a press briefing before the meeting.
Oropharyngeal cancer "can now be divided into those linked to prolonged use of tobacco and alcohol, and those linked to HPV," she said. And determining HPV status, she added, "may now be part of routine clinical care…because of its prognostic implications in these patients."
The findings come from a correlative study in the Radiation Therapy Oncology Group 4 (RTOG) 0129 clinical trial 5, a phase III trial in which patients with stage III or IV oropharyngeal cancer were randomly assigned to receive different regimens of radiotherapy and the chemotherapy drug cisplatin 6. Nearly two-thirds of the tumor samples tested HPV positive, Dr. Gillison said. Two years after treatment, 88 percent of the HPV-positive patients were still alive, compared with 66 percent of the HPV-negative patients. The absolute difference in survival increased over time.
Additional analyses ruled out other factors, such as age, performance status, and treatment, that might account for the superior outcomes seen in patients with HPV-positive tumors.
Due to the dramatic differences in treatment response, Dr. Gillison said, from this point forward RTOG and the Eastern Clinical Oncology Group 7 will stratify all of their clinical trials by HPV status, and they will design clinical trials specifically for HPV-positive or -negative patients.