Where in the body do head and neck cancers form?

Head and neck cancers can form in several areas: the oral cavity (mouth), the throat (pharynx), the voice box (larynx), the paranasal sinuses and nasal cavity, and the salivary glands. Most begin in the squamous cells that line the moist surfaces inside these areas.

That shared cell type is why these sites are grouped at all. Squamous cells form the thin, flat lining of the mouth, throat, and airway. They sit at the front line. They touch whatever you breathe, drink, chew, or swallow. Cancers that start in them share risk factors. They often respond to similar treatments, even when they begin inches apart. Salivary gland cancers are the exception here, because they start in gland tissue rather than that surface lining.

The throat, or pharynx, has three parts: the nasopharynx behind the nose, the oropharynx in the middle (including the tonsils and base of the tongue), and the hypopharynx at the bottom.

Those three parts are not trivia. They sit within an inch or two of each other. Yet they differ in usual cause, usual treatment, and usual outcome. "Throat cancer" is too vague to be useful. The exact part is what your team plans around.

Cancers of the brain, the eye, the esophagus, the thyroid gland, and the skin of the head and neck are not usually classified as head and neck cancers, even though they are in the same region. They start from different tissue and behave differently. So they get their own categories and their own treatment paths.

The main causes are well established. Tobacco and alcohol are the two most important risk factors. Certain cancer-causing types of human papillomavirus raise the risk of cancer in the oropharynx, and HPV type 16 most of all. Epstein-Barr virus is a risk factor for cancer of the nasopharynx and the salivary glands. Paan, also called betel quid, is held in the mouth and is strongly linked to mouth cancers.

One trend is reshaping this whole group. In the United States, cancers of the oropharynx caused by HPV are rising. Cancers of the same area from other causes are falling. Tobacco and alcohol no longer explain every case. That is one reason a sore throat that will not go away, or a lump in the neck, deserves a look even in someone who never smoked.

For scale, NCI reported that more than 68,000 men and women in the United States would be diagnosed with head and neck cancers in 2021. That is close to 4% of all cancers.

Your healthcare team can explain more about a specific type. Two things are worth pinning down early. First, get the exact site in writing, such as "oropharynx, base of tongue." A general label will make everything you read afterward less accurate. Second, if the cancer is in the oropharynx, ask whether the tumor was tested for HPV. That result is part of knowing which version of this disease you have.