Clinical Advances in HPV-Positive Head and Neck Cancer - Episode 2
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Barbara Murphy, MD, states that most people living in the United States will be exposed to Human Papilloma Virus (HPV) at some point during their adult lives. When patients hear that HPV is a sexually transmitted virus, they associate sexual transmission with promiscuity, but that is seldom the case, says Murphy.
Because certain HPV strains have been shown to cause cancer, patients often have a lot of questions, including the likelihood of transmitting the virus to their partners and whether their partners will be at increased risk for cancer. Murphy notes the importance of being prepared to answer these questions in head and neck cancer (HNC) patients and mentions the utility of online resources for patients and their loved ones.
In HNC, HPV is responsible for 70% to 80% of oropharynx cancers and appears to selectively cause cancer in the oropharynx, says Robert Ferris, MD. The disease is more common in men (incidence is approximately 4 males for every 1 female), and discovery often begins when men notice a lump in their necks while shaving.
Diagnosis is confirmed with a biopsy via fine needle aspiration, which can be performed in an office setting. DNA from the virus itself can also be analyzed through polymerase chain reaction (PCR). The most commonly used and most practical methodology, however, is immunohistochemistry, says Ezra Cohen, MD. In this setting, immunohistochemistry detects for a protein called P16, whose expression is upregulated in HPV disease. The standard reported across the country is 70% of cancer cells stain positive for P16, consistent with about a 95% concordance with HPV positivity. Cohen notes to keep in mind there are some HPV positive cancers that will not stain for P16, as immunohistochemistry is not 100%.
Knowledge of HPV-associated HNC remains premature, and current guidelines do not address specific management of HPV-associated tumors. Cohen adds that HPV-positive cancers fare significantly better than HPV-negative counterparts, but knowing a disease is HPV-positive does not change management. Many randomized phase III trials investigating optimal treatment of HPV-positive disease are ongoing, which Murphy states will probably serve as the basis for future treatment guidelines.
Currently, HPV-positive HNC patients are treated just as any other squamous cell carcinoma of the head and neck would be treated, which, depending on patient preference, site of expertise, and size of the tumor, typically involves multidisciplinary care consisting of chemotherapy, radiation, and surgery.