Head and neck cancer begins with the abnormal growth of cells. These cells multiply out of control, eventually forming a tumor in part of the head or neck. As the tumor grows, it can form a lump, a sore, or an abnormal patch of white or discolored tissue. Without treatment, the tumor can invade and destroy nearby bones and soft tissues. Eventually, it can spread (metastasize) to lymph nodes in the neck and to other parts of the body.
In many cases, head and neck cancers are triggered by carcinogens. These are substances that cause cancer. Common carcinogens include tobacco smoke, smokeless (chewing) tobacco, and snuff. Chronic or heavy alcohol use also contributes to head and neck cancer. The disease is especially prevalent in those who both use tobacco and drink alcohol. The human papilloma virus (HPV), which causes cervical cancer in women, has been linked to a growing number of throat cancers in men. Although a cause and effect relationship has not been proven, oral sex may be to blame for the transmission of HPV.
Head and neck cancers are classified based on where they are found:
Upper aerodigestive tract This includes the lips, tongue, mouth, throat, and voice box (larynx). Of all head and neck cancers, those involving the upper aerodigestive tract are the most common. Almost all cancers in this part of the head are squamous cell carcinomas, which arise from cells that line structures in the head and neck. Squamous cell carcinomas can also occur on the skin of the head and neck, but they are not considered to be skin cancer.
Upper aerodigestive tract cancers are more common in people over age 45. Men are affected two to four times more often than women. Most of these cancers are related to tobacco use. Alcohol increases the risk, especially when it's used heavily and constantly. More and more cases of throat cancer in men have been tied to HPV.
Salivary glands Salivary gland cancer is rare and varies in aggressiveness. Exposure to radiation increases the risk of this type of cancer. Smoking may play a role in certain types of salivary gland cancer. People who have had chronic salivary gland stones and inflammation of the salivary glands may be more prone to this disease.
Nasopharynx The nasopharynx is the upper portion of the back of the throat, where the throat meets the back of the nasal cavity. Unlike other head and neck cancers, this one is not associated with tobacco or alcohol use.
In the United States, nasopharyngeal cancer has not been associated with any particular cause. But in parts of northern Africa, Asia, and the Arctic, where this cancer is more common, it has been linked to infection with the Epstein-Barr virus, the cause of infectious mononucleosis; eating Cantonese salted fish; high exposure to dust and smoke; and eating a lot of fermented foods.
Sinuses and nasal cavity About three-quarters of cancers found in the sinuses (behind the bones of the forehead and cheeks and inside the nose) are squamous cell carcinomas. Rarely, other types of cancer occur in this area. In many cases, these cancers grow fairly large before they are diagnosed. This is because the tumors have room to grow before they block the sinuses or nasal passages or cause other symptoms.