Dr. Kim's study on HPV-positive oropharyngeal cancers published in New England Journal of Medicine
Tuesday, June 29, 2010
Harold Kim, M.D., an associate professor of Radiation Oncology at the Barbara Ann Karmanos Cancer Institute and Wayne State University School of Medicine, has co-authored a New England Journal of Medicine article that details study findings that show cancers of the mouth and throat caused by human papillomavirus (HPV) indicate a more favorable survival rate than similar cancers associated with other causes.
The findings may one day lead to specialized, less-intense treatment for those with HPV-positive oropharyngeal (OP) carcinoma.
Dr. Kim co-wrote the article, titled, “Human Papillomavirus and Survival of Patients with Oropharyngeal Cancer.” The article was published in the June edition of the New England Journal of Medicine.
The study found that in oropharyngeal cancer (carcinomas in the middle part of the throat, including the base of the tongue, the tonsils and soft palate), the HPV-positive form of cancer demonstrates a different biological response to chemoradiation treatment than smoking-related HPV-negative cancer, according to Dr. Kim.
“This study may lead to the development of less-intense treatment regimens for HPV-positive OP cancer patients, reducing treatment-related side effects,” he said.
The researchers conducted an analysis of the association between tumor HPV status and survival among patients with Stage III or Stage IV oropharyngeal squamous-cell carcinoma that are enrolled in a randomized trial comparing accelerated-fractionation radiotherapy with standard-fractionation radiotherapy, each combined with cisplatin (a chemotherapy drug).
A total of 63.8 percent of the patients had HPV-positive tumors. They displayed better three-year overall survival rates (82.4 percent) vs. those with HPV-negative cancers (57.1 percent). After adjusting for age, race, tumor stage and tobacco exposure, the patients with HPV positivity displayed a 58 percent reduction in death risk.
The study, according to Dr. Kim, provides “strong evidence” a tumor’s HPV status is an independent prognostic factor for overall survival and progression-free survival in patients with oropharyngeal squamous-cell cancers.
“The higher survival rate for HPV-positivity patients is mainly due to better local and regional control compared to HPV-negative patients, which implies that HPV-positive oropharyngeal cancers are more sensitive to chemoradiation treatments,” Dr. Kim said.
While tumor suppressor gene P-16 has been implicated in the differentiation, “the exact mechanism of this enhanced sensitivity to chemoradiation in HPV-positive oropharyngeal cancer still needs to be investigated. HPV status should be used, along with other prognostic factors, in stratifying patients into different risk categories in future trials,” he said.
Dr. Kim recommends that future trials should test whether HPV-positive oropharyngeal cancer patients can be treated with a less-intense chemoradiation regimen without compromising local-regional control or survival.
In addition to Dr. Kim, research team members come from the University of Texas M.D. Anderson Cancer Center, Houston; the Radiation Therapy Oncology Group Statistical Center and Thomas Jefferson University Hospital, Philadelphia; Huntsman Cancer Institute, Salt Lake City; Centre Hospitalier de l’Universite de Montreal,
Montreal; Johns Hopkins University, Baltimore; Vanderbilt University School of Medicine, Nashville; University of Louisville, Louisville, Ky.; University of California at San Francisco; University of Cincinnati College of Medicine; and the Ohio State University Comprehensive Cancer Center.