Which cancers have increased over the past decade?
Key Takeaways
The incidence of cancers at the level of the oral cavity and pharynx increased between 2007 and 2016, according to a recent report by researchers from the CDC published in Morbidity and Mortality Weekly Report. This rise occurred despite respective decreases in the incidence of cancers at various anatomic sites.
Cancers of the oral cavity and pharynx make up 3% of cancers diagnosed in the United States each year, with risk factors including tobacco use, HPV infection, and excessive alcohol intake.
“The overall increase appears to be driven by increases in cancers of the tonsil, base of tongue, oropharynx, and other cancers of the oral cavity and pharynx, which are HPV-associated, as well as by those of gum and anterior tongue,” wrote the authors.
Breaking down the numbers
On average, the incidence rates for cancers of the oral cavity and pharynx combined increased by 0.6% per year between 2007 and 2016, with specific increases as follows:
Oral cavity and pharynx (3.4%)
Base of tongue (1.8%)
Anterior tongue (1.8%)
Gum (1.9%)
Tonsil (2.4%)
Oropharynx (1.9%)
For the following cancers, however, incidence rates decreased:
Soft palate and uvula (−3.7%)
Hard palate (−0.9%)
Floor of mouth (−3.1%)
Lip (−2.7%)
Hypopharynx (−2.4%)
Nasopharynx (−1.3%)
Of note, the incidence of cheek and other mouth and salivary gland cancers remained unchanged.
Sorting demographics
Per the data, the incidence of all cancers of the oral cavity and pharynx increased among men but remained unchanged among women. Cancer rates were stable among participants aged 20-39 years and in those aged 80 years or older, decreased in those 40-49 years, but increased in those 50-79 years. The overall increase in rate trends at specific sites of cancer were mostly due to the bump in the incidence of cancers in those 50-79 years, noted the researchers.
Rates increased in white and Asian individuals, as well as those of Pacific Islander descent; decreased in African American and Hispanic individuals; and remained unchanged among American Indians and Alaska Natives. Notably, when parsed by race/ethnicity, anatomic sites of cancer with heightened rates occurred mostly only among white individuals, with few exceptions.
Decreasing tobacco use
The researchers cited drops in tobacco use as a possible reason for the decreased incidence of certain types of oral cavity and pharynx cancers. Nevertheless, the use of tobacco and alcohol are still common among Americans, with 14% of adults identified as current smokers and 27% reporting binge-drinking habits.
“Population-based tobacco control measures (including high-impact anti-tobacco mass media campaigns, tobacco price increases, and comprehensive smoke-free laws) are proven to prevent tobacco use initiation and promote smoking cessation, but they are not implemented equally in all US states and communities,” the authors reflected. “Similarly, state alcohol control policies and alcohol screening are effective in reducing excessive alcohol use but are underutilized.”
The authors recommended broader application of evidence-based interventions and targeted efforts focused on demographic use—with particular attention placed on those with high rates of tobacco use, alcohol use, or high cancer rates—to lower rates of oral cavity/pharynx cancers.
Considering HPV-related cancers
The incidence of HPV-associated cancers—which include squamous cell cancer types at the base of tongue, pharyngeal tonsils, anterior and posterior tonsillar pillars, glossotonsillar sulci, soft palate and uvula, and lateral and posterior pharyngeal walls—went up by 2.1% a year, on average, compared with cancers not linked to HPV, which decreased by an average of 0.4% per year.
Public health efforts should hone in on HPV vaccination to decrease the incidence of oral cavity and pharynx cancers, according to the researchers. Such vaccination is recommended for those aged 11 or 12 years, with catch-up vaccination available through 26 years.
Intriguingly, the authors noted that no data on the vaccination efficacy of oral cavity/pharynx cancers exist from clinical trials. However, available vaccines target cancers caused by HPV.
Citing limitations
The authors cited three specific limitations to the findings in their report. First, cancer reporting delays could have resulted in rate underestimation. Second, cancer registries often fail to record data reflecting HPV infection, tobacco use, or alcohol use; therefore, it was not possible to ascertain whether cancers may have developed in individuals exposed to these risk factors. Third, because it was difficult to determine and classify where cancers originated due to anatomical complexities, some cases may have been misclassified.
“Broader application of proven strategies to prevent tobacco use initiation, promote smoking cessation, reduce excessive alcohol consumption, and increase HPV vaccination rates can help reduce the incidence of these cancers,” concluded the authors.