Mouth and Throat Cancers Rose in 2007–2016, Driven by HPV-Linked Sites

Cancers of the oral cavity and pharynx — the mouth and throat — make up 3% of cancers diagnosed in the United States each year. They occur at several distinct sites, with different tissue types and different causes: tobacco, alcohol and human papillomavirus (HPV). Combined, their incidence fell during the 1980s and began rising again around 1999. Since tobacco use and many tobacco-related cancers have declined, researchers suspected the rise lay at sites where HPV DNA is often found.

A CDC team — Taylor D. Ellington, S. Jane Henley and colleagues in the Division of Cancer Prevention and Control — tested that with U.S. Cancer Statistics data covering the entire U.S. population for 2007–2016, including only microscopically confirmed cases.

The overall trend

New cases rose from 35,076 in 2007 to 44,419 in 2016, and the age-adjusted rate from 10.89 to 11.7 per 100,000, an average rise of 0.6% a year. Over the decade there were 400,291 cases in all.

Average annual change in incidence by site, 2007–2016. Credit: CDC, MMWR.

Site by site

"HPV-associated" means squamous cell cancers at sites where HPV DNA is frequently found. Changes are average annual percentage changes in age-adjusted rates, all statistically significant except the stable sites. Source: CDC, MMWR.

The rise was driven by HPV-associated cancers of the tonsil, base of tongue, oropharynx and other oral cavity and pharynx, along with cancers of the gum and anterior tongue. Falling tobacco use may explain the declines at some other sites.

Who saw the increase

• Sex. Combined rates rose among men (+0.7% a year) but were stable among women. Women saw increases in cancers of the anterior tongue, gum and tonsil, and decreases in floor-of-mouth, soft palate and uvula, nasopharynx and hypopharynx cancers. Men followed a similar pattern, with added decreases in lip cancer and increases at the base of tongue, oropharynx and other sites.
• Age. Combined rates rose among people aged 50–79, fell among those 40–49, and were stable at 20–39 and 80 and older. Rising sites were driven mostly by people aged 50–79.
• Race and ethnicity. Rates rose among white (+1.1% a year) and Asian/Pacific Islander (+0.9%) people, were stable among American Indian/Alaska Native people, and fell among Black (−1.5%) and Hispanic (−0.9%) people. An earlier study found oropharyngeal squamous cell cancers rising fastest among white men, who report starting oral sex earlier and having more oral sex partners than other groups — both risk factors for HPV exposure.

Prevention

• Tobacco. Mass-media campaigns, higher tobacco prices and comprehensive smoke-free laws are proven to stop people starting and help them quit, but are applied unevenly across states and communities. In 2018, 14% of U.S. adults smoked cigarettes.
• Alcohol. State alcohol-control policies and alcohol screening reduce excessive drinking but are underused. In 2018, 27% of adults reported binge drinking.
• HPV vaccination. Routine vaccination is recommended for everyone at age 11 or 12, with catch-up through age 26. No clinical trial has measured its effect on mouth and throat cancers, but these cancers are caused by HPV types the vaccines target. CDC's National Comprehensive Cancer Control Program supports prevention in every state, D.C., tribal organizations and the territories, and with CDC's immunization center funds the American Cancer Society's National HPV Vaccination Roundtable.

Limitations

1. Reporting delays may mean incidence is underestimated.
2. Registries do not routinely record HPV infection, tobacco or alcohol use, so cases could not be tied to exposures.
3. In an anatomically complex region, some cancers may have been assigned to the wrong site.

Sources

Based on Ellington TD, Henley SJ, Senkomago V, et al., "Trends in Incidence of Cancers of the Oral Cavity and Pharynx — United States 2007–2016," MMWR, Centers for Disease Control and Prevention; a work of the United States government in the public domain.