Certain head and neck cancers that are positive for high-risk types of human papillomavirus (HPV) have a better prognosis and may need less aggressive treatment.
To help ensure that patients with these cancers are accurately diagnosed and effectively treated, the College of American Pathologists (CAP) today released its newest evidence-based practice guideline, "Human Papillomavirus (HPV) Testing in Head and Neck Carcinomas,"
The guideline comes at a much-needed time. HPV-positive head and neck cancer is on the rise in the U.S., with the greatest increase among middle-aged Caucasian men. In the United States and Canada, high-risk HPV causes approximately 70% of cancers of the oropharynx (those involving the middle of the throat, the base of the tongue, and the tonsils), according to the National Cancer Institute.
"Accurate HPV assessment in head and neck cancers is becoming critical," said guideline co-chair William C. Faquin, MD, PhD, FCAP, a pathologist at Massachusetts General Hospital, Boston. "It is also important to know when testing is not indicated, and this new guideline provides that guidance."
An interdisciplinary, expert panel of pathologists, surgeons, radiation oncologists, medical oncologists, patients, and patient advocates developed the guideline, which recommends accurate assessments of a patient's high-risk HPV status, directly or by surrogate markers.
"Because today's cancer care is increasingly multidisciplinary, a diversity of disciplines of the members for this expert panel was critical. This provides strength to the recommendations," said project co-chair, James S. Lewis, Jr., MD, FCAP, a pathologist at Vanderbilt University Medical Center in Nashville, Tenn.
Based on a screening of 2,200 peer-reviewed articles and a review of evidence from 492 studies, the panel issued 14 final recommendations in the guideline. Notably:
- High-risk (HR) HPV testing should be performed on all patients with newly diagnosed oropharyngeal squamous cell carcinoma (OPSCC), including all histologic subtypes.
- HR-HPV testing should not be routinely performed on nonsquamous carcinomas of the oropharynx, nor on nonoropharyngeal primary carcinomas of the head and neck.
- Because marked overexpression of the tumor suppressor protein p16 is strongly associated with transcriptionally-active high-risk HPV, pathologists should perform HR-HPV testing by surrogate marker p16 immunohistochemistry on oropharyngeal tissue specimens (i.e., non cytology). Additional HPV-specific testing may be done at the discretion of the pathologist, treating clinician, or in the context of a clinical trial.
- For HPV-positive/p16 cases, tumor grade (or differentiation status) is not recommended.
"HPV-associated carcinomas of the oropharynx are different biologically and clinically, and this impacts the patient's treatment plan," said panelist and surgical oncologist James Rocco, MD, PhD, The Ohio State University Wexner Cancer Center, Columbus, Ohio. "We have many tools in the cancer-fighting arsenal, and this guideline will help inform the entire treatment team on which tools to use and when."
Panelist and Stanford University radiation oncologist Beth Beadle, MD, concurs. "Management of these patients can involve a combination of radiation, chemotherapy, and/or surgery. By better tailoring the treatment to the specific pathology of each patient's cancer, we can achieve better results and help minimize side effects," she said. Many clinical trials aimed at tailoring treatment for HPV-positive OPSCCs are underway.
The CAP Pathology and Laboratory Quality Center develops evidence-based guidelines and consensus statements related to the practice of pathology and laboratory medicine. Through this work, the CAP and its members continually improve the quality of diagnostic medicine and patient outcomes.