There are a variety of known risk factors for head and neck cancer, defined below.
Alcohol and tobacco use represent 75% of the risk factors, especially of cancers of the oral cavity, oropharynx (part of the throat at the back of the mouth), hypopharynx (lower part of the throat at the back of the mouth), and larynx or voice box. People who use both tobacco and alcohol are at greater risk of developing these cancers than people who use either tobacco or alcohol alone.
Infection with cancer-causing types of human papillomavirus (HPV), especially HPV type 16, particularly affects the tonsils or the base of the tongue. The incidence of oropharyngeal cancers caused by HPV infection is increasing, although the incidence of these cancers related to other causes is falling. (National Cancer Institute)
Radiation exposure for non-cancerous reasons is a risk factor for salivary gland cancers.
Exposure to wood dust, asbestos and synthetic fabrics has been associated with cancers of the larynx and nasopharyngeal (part of the nose at the back of the throat) region. Industrial exposure to wood or nickel dust or formaldehyde is also a risk factor for cancers of the paranasal sinuses and nasal cavity.
Epstein-Barr virus is a risk factor for nasopharyngeal cancer and cancer of the salivary glands.
Asian ancestry, particularly Chinese ancestry, is a risk factor for nasopharyngeal cancer.