Head and neck cancers are a group of cancers that originate from the base of skull to the clavicles. It comprises diverse diagnoses of cancers that begin in the sinuses, throat, mouth, salivary glands, and larynx. Cancers in this region have a variety of causes including use of alcohol and tobacco. Head and neck cancers often present as a lump or sore that does not go away. It can be painful or painless. In some cases, the mass can cause difficulty swallowing or even breathing and may cause a hoarse voice. There are many non-malignant causes of these symptoms and concerned patients should be evaluated by a physician or dentist.
A biopsy is necessary for the definitive diagnosis of cancer and provides information about the cancer which can inform treatment decisions. Once a diagnosis has been made, careful examination is undertaken to determine the extent (or stage) of the cancer. The staging process can include examination under anesthesia, various imaging modalities, and laboratory studies. The result of staging is our best determination of the local extent of the tumor (T stage), the extent of involvement of regional lymph nodes (N stage), and whether the cancer has spread distantly through the blood to other organs (M stage).
Treatment options for cancers of the head and neck include surgery, radiotherapy, or systemic therapy (including chemotherapy, immunotherapy, or other targeted drug therapy). Patients may receive one, two, or a combination of all three treatment modalities. Ultimately, treatment recommendations are dependent on the goal of therapy, the site of origin, the biology of the cancer, and the stage.
Surgery is often employed when we believe that all malignant tissue can be safely separated from healthy tissue. Radiation therapy uses the fact that healthy tissue is able to repair small amounts of radiation damage while cancer cells cannot. As such, we are able to deliver repeated radiation doses to eliminate cancer cells from tissue that is not easily removed by a surgeon. Chemotherapy is used in low doses to augment radiation therapy or as monotherapy in the treatment of metastatic disease.
A rising number of patients are being diagnosed with head and neck cancers associated with human papilloma virus (HPV) infection. Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States. There is no cure for HPV but the majority clear infection. It is not clear why some can get rid of HPV infection, while others cannot. A few high-risk strains, primarily HPV-16, can cause persistent infection and ultimately lead to malignancy.
HPV is associated with head and neck, cervical, vaginal, vulvar and anal cancers. The risk factors for HPV-associated head and neck cancers are similar to cervical cancers—multiple sexual partners, a younger age for the first sexual encounter, oral sex and genital warts. Prophylactic HPV vaccines can prevent infections and thus resultant tumors from HPV vaccine viruses. However, the vaccine is only effective if given before infection occurs. Thus, HPV vaccination is recommended in early adolescence before sexual exposure.
The incidence of HPV-associated head and neck cancers has been increasing over the years. HPV-positive head and neck cancers, particularly arising in the base of the tongue and in the tonsillar region, are typically seen in younger people without significant alcohol or tobacco abuse. These tumors behave aggressively with earlier and more extensive lymph node involvement. However, the prognosis of HPV-positive head and neck cancers is significantly better compared to HPV-negative cancers. This is attributed to the different biology of HPV-positive cancers.
Multiple clinical trials are currently underway to optimize treatments for HPV-positive head and neck cancers, with an emphasis on treatment de-escalation to minimize long term treatment related complications without compromising efficacy and prognosis.