PAHO/WHO — Rates of oral cancer caused by the human papillomavirus (HPV) have more than tripled in the United States in the past two decades, even as other types of oral cancer have been declining in the United States and worldwide.
Why HPV-related oral cancers are on the rise, whether they are increasing in other countries, and what can be done about it are the focus of an international consultation being held this week at the Pan American Health Organization/World Health Organization (PAHO/WHO).
The consultation brings together experts from the U.S. National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health (NIH), the International Association for Dental Research (IADR), the American Dental Association (ADA), and others to examine what is known about the epidemiology and biology of HPV-related oral cancer, its risk factors, prevention, screening, diagnosis, and treatment. The consultation is expected to conclude with a series of recommendations for new research and public health policies to address the problem in the Americas.
“Oral cancer associated with HPV is an important emerging health problem,” said Dr. Saskia Estupinan-Day, head of PAHO/WHO’s Oral Health Program. “We need more research on the problem, but we also need to develop and implement public health policies to help stem the rise of this disease.”
The incidence of HPV-associated oral cancers has risen 225% in the United States during the past two decades, according to data published in the Journal of the American Dental Association. Rates of other oral cancers—usually related to tobacco and alcohol use—have been declining. Worldwide, there were an estimated 443,000 new cases of oral cancer of all types and 241,000 deaths in 2012, the most recent year for which global data are available.
Data are lacking on HPV-related oral cancer in the countries of Latin America and the Caribbean. There are also significant gaps in scientific knowledge about HPV infections, their persistence, and associated oral cancers in the general population and in HIV-infected individuals. Evidence is also lacking on the efficacy of HPV vaccines to prevent HPV-associated oral cancer, which could prove to be an important tool for prevention.
HPV is better known as the cause of cervical cancer in women but also causes other anogenital cancers, head and neck cancers, and genital warts in both men and women. The virus spreads through direct skin-to-skin contact, primarily through vaginal, anal, or oral sex. Younger people, males, and people with more sexual partners are at higher risk.
In parallel to the surge of HPV-associated oral cancers in the general U.S. population over the past 20 years, cases of both oral and tonsil cancer have at least doubled among individuals with HIV/AIDS, who are at elevated risk due to their weakened immune systems. If current trends continue, the annual number of HPV-associated oral cancers in U.S. men is expected to exceed cervical cancer cases in U.S. women by the year 2020.
“The increase in HPV-associated oral cancer globally is a growing public health problem in the general population and is exacerbated in individuals infected with HIV,” said Dr. Isaac Rodriguez-Chavez, Director of the AIDS and Immunosuppression Program at NIDCR, NIH. “This international consultation will help us take stock of what we know, define what we still need to know, and begin to harmonize global efforts following multipronged approaches to address this emerging problem.”
One promising approach to prevention of HPV-related oral cancers is immunization. Currently, two vaccines are known to protect against HPV infections that have been linked with cervical cancer. However the vaccines’ effectiveness in preventing oral cancer has not been determined. To date, 23 countries and territories of the Americas have introduced the HPV vaccine, potentially covering 85% of adolescent girls throughout the region.
The international consultation was organized by PAHO/WHO with support from NIH, NIDCR, IADR, ADA, and the American Dental Association Foundation (ADAF). Participants also included academicians and researchers from Australia, Canada, and the United States as well as representatives of WHO’s International Agency for Research on Cancer (IARC), the U.S. Public Health Service, the U.S. Centers for Disease Control and Prevention (CDC), and the ministries of health of the Bahamas, Chile, and Jamaica.