Editor's note: Unedited b-roll of Dr. Moira Sutton speaking to this topic is available for media. Download 720p version here. Download the SD version here.
Human papillomavirus (HPV) is the leading cause of oropharyngeal cancer, or cancer that develops at the base of the tongue, tonsils, soft palate and throat. The National Cancer Institute reports that about 70 percent of oropharyngeal cancer is caused by HPV, specifically the HPV 16 strain.
The American Cancer Society estimates that approximately 45,800 people will get oral oropharyngeal cancer in 2015, and 8,700 people will die from this type of cancer this year. The incidence of cancer affecting this part of the body has increased 225 percent from 1988 to 2004, according to a study published in the Journal of Clinical Oncology.
The incidence of cancer of the tongue and throat caused specifically by HPV is on the rise.
“Oropharyngeal cancer caused by HPV is not one of the most common types of cancer like prostate, breast or skin cancer. There are about 13,000 cases per year,” said Dr. Moira Sutton, a radiation oncologist at Novant Health UVA Health System Cancer Center at Lake Manassas in Gainesville, Virginia. “It’s predicted that with the new HPV-associated oropharyngeal cancer, there will be about 20,000 new cases by 2030.”
Sutton said that in the past most of the cases of oropharyngeal cancer were caused by smoking or drinking, but now the diagnosis is increasingly among nonsmokers infected with HPV.
“The connection between oral cancer and HPV is something that we’re only starting to appreciate in recent years,” she said. “In the late ‘90s and early 2000s, the typical patient with oropharyngeal cancer was a heavy smoker or drinker and it’s only in the past 10 years that we’ve seen this sudden rise in nonsmoking men with oropharyngeal cancer and those found to be HPV-positive,” Sutton added.
Men seem to be most susceptible to this type of cancer. “The rate of infection with HPV in the oral cavity is much more common in males,” Sutton said. “The ratio is about 5 to 1 males versus females. The typical patient with oropharyngeal cancer that we see now is a male in their 40s or 50s.
In the United States, HPV infections are the most common sexually transmitted infections. The Centers for Disease Control and Prevention estimates that more than 90 percent and 80 percent of sexually active men and women, respectively, will become infected at some point during their lives. The agency points out about half of these infections involve the high-risk type of virus.
In most cases involving high-risk HPV, the infections will clear within a year or two and won’t cause cancer. However, persistent infections can lead to cell mutations and may progress to cancer, according to the National Cancer Institute.
Studies are unclear about how people contract oral HPV. The CDC reports that some research shows that it can be passed through oral sex or French kissing. The most common risk factors for oral cancer remain smoking and alcohol use. Some studies have also found that diets low in fruit and vegetables are linked to a higher incidence of oral cancer.
“The problem is that once you get infected with HPV, it takes about 20 to 30 years before the cancer develops,” Sutton said.
Symptoms of oropharyngeal cancer can include persistent sore throat, earaches, hoarseness, enlarged lymph nodes, pain when swallowing and unexplained weight loss, though the CDC cautions some people may exhibit no symptoms.
Sutton said oropharyngeal cancer can be very hard to detect. “Dentists generally will do a cancer screening, but these are cancers that tend to be in the back of the tongue, the tonsillar area that are not easily seen in a routine dental exam,” she said. “So generally, patients aren’t found to have it until they have symptoms such as pain or difficulty swallowing.”
In many cases, by the time the cancer is diagnosed, patients may already have stage 4 cancer with lymph node involvement, according to Sutton. And while radiation and chemotherapy can cure most patients, Sutton warned that it is one of the toughest cancer treatment regimens with consequences affecting quality of life.
The HPV 16 strain also causes cervical and anal cancer. But unlike cervical cancer screening, there is no test equivalent to the Pap smear for early detection in oral cavity cancer.
“These HPV cancers are preventable with vaccination,” said Sutton. “A lot of people think of the HPV vaccine as a girls’ vaccine. Many people know that it used to prevent cervical cancer but people don’t realize that it can also prevent people from getting oropharyngeal cancers.”
To prevent an HPV infection, the National Cancer Institute recommends an HPV vaccine before a person becomes sexually active. Two vaccines, Gardasil and Cervarix, are approved for use by the U.S. Food and Drug Administration in the prevention of the virus. While these vaccines do protect against new infections, they do not treat existing HPV infections or the disease brought on by the infection.
Researchers at the NCI found in a recent study that the HPV vaccine protects women from oral infections as well as cervical infections.
“It’s important for these young boys and girls to be vaccinated at around 11 to 12 as per the CDC recommendation and for parents not to think of it just as a girls’ vaccine,” Sutton said.
The CDC recommends the vaccines for boys and girls ages 11 and 12, and for boys and young men ages 13 through 21 as well as girls and young women ages 13 to 26 who have not already had all three shots. Vaccinations may also be given to children as young as age 9 and to men between the ages of 22 and 26.