HPV status predicts outcomes of oropharyngeal cancers

Jun 1, 2009

Patients with advanced oropharyngeal cancer whose tumors contain the human papilloma virus (HPV) have better outcomes than patients who do not, according to research conducted by the Radiation Therapy Oncology Group (RTOG) and presented at the American Society of Clinical Oncology (ASCO) annual meeting being held this week in Orlando, FL.

Although earlier trials also reached this conclusion, they did not have a large enough sample size to factor in patient age and a range of tumor sizes, as well as include both smoking and nonsmoking patients.

The RTOG phase III clinical trial (RTOG 0129) enrolled 206 patients who were HPV-positive and 117 patients who were HPV-negative. The patients received a combination of radiation therapy and chemotherapy, according to principal investigator Dr. Maura Gillison, Ph.D., professor of medicine, epidemiology, and otolaryngology at Ohio State University in Columbus.

Gillison and colleagues compared the time it took for cancer to progress or the patient to die. At two years, 87.9% of HPV-positive patients were still alive, compared with 65.8% of HPV-negative patients.

Two-year progression-free survival was 71.8% for the HPV-positive group and 50.4% for the HPV-negative group. After five years, the incidence of second primary cancers among HPV-positive patients was 9.0%, compared with 18.5% for HPV-negative patients.

Because of these findings, Gillison said that future trials need to stratify patients by their HPV status. Other studies are being designed to assess the efficacy of the HPV vaccine for preventing these cancers.

When this trial was initiated in 2002, it was not intended to compare the progression-free and survival outcomes of the two groups, according to Dr. Walter Curran Jr., RTOG chair and chief medical officer of Emory Winship Cancer Institute in Atlanta.

He noted that because RTOG has made it a priority to prospectively collect material for future marker analyses, when the findings of the earlier trials were presented, a decision was made to conduct an outcomes comparison for patients with cancers of the upper throat.