Scientists do not completely understand what causes throat cancers, although the role of some risk factors has been established. For example, use of tobacco and excessive drinking damage cells. Tobacco use damages cell DNA, while alcohol increases the sensitivity of cells to DNA-damaging chemicals. The damage to DNA creates abnormalities that can produce tumors.  For this reason, the combination of alcohol use and tobacco use is especially dangerous and increases the risk of developing throat cancers.

The risk factors associated with throat cancer can be divided into two groups: those that affect oropharyngeal, laryngeal and hypopharyngeal cancers and those that affect nasopharyngeal cancer.

Risk factors associated with oropharyngeal, laryngeal and hypopharyngeal cancers include:

• Human papillomavirus (HPV) infection. Papillomaviruses are a group of more than 100 related viruses, many of which may cause warts on various parts of the body. HPV may contribute to oropharyngeal cancers in about 20 percent of people, and may also be a factor in laryngeal and hypopharyngeal cancers.
  
  
• Suppressed immune system. Patients who are taking immunosuppressive drugs to either treat various immune-system diseases or prevent rejection of transplanted organs may be at greater risk for these cancers.
  
  
• Dietary factors. Malnutrition and vitamin deficiencies may be related to an increased risk of throat cancers. Eating smoked or salt-preserved foods, which contain nitrates, has also been associated with increased risk.
  
  
• Occupational exposure. Long and intense exposures to industrial chemicals such as metalworking chemicals or asbestos may increase the risk.
  
  
• Recreational drugs. The use of drugs such as marijuana has been linked to a higher incidence of throat cancers.
  
  
• Age. Throat cancers are very rare in children. The risk of being diagnosed with these cancers increases with age. For example, half of all patients are older than age 65.
  
  
• Gender. Oropharyngeal cancer is twice as common in men as in women. Meanwhile, laryngeal and hypopharyngeal cancers are four to five times as common in men as women. This may be related to increased use of alcohol and tobacco among men.
  
  
• Race. African Americans are much more likely to be diagnosed with these cancers than whites.

Nasopharyngeal cancer risks include:

• Diet. NPC has been associated with diets high in salt-cured fish and meat, such as those of people in areas of Asia, northern Africa and the Arctic region.
  
  
• Epstein-Barr virus infection. Almost all nasopharyngeal cancer cells contain the Epstein-Barr virus (EBV), an infection that causes infectious mononucleosis, commonly known as “mono.” The link between EBV infection and NPC is not well-understood.
  
  
• Gender. Males are twice as likely to be diagnosed as females.