HPV viruses linked to growth in oral cancers
Howard Manly | , Karen Miller | 8/12/2013, 11:27 a.m.
While the annual report on the status of cancer in this country indicated a decline in the incidence and death rates of all cancers combined, some particular cancers did not fare that well. HPV-related cancer of the throat is one of them.
You don’t have to explain that to Dr. Robert I. Haddad, the disease center leader of the Head and Neck Oncology Program at Dana-Farber Cancer Institute. “I see two patients a week for HPV-related head and neck cancer,” he explained. “It’s very common and now the number one cause of oropharyngeal cancer.”
Oropharyngeal cancer affects the throat, back of the tongue and tonsils. For HPV-associated cancers, it trails only cervical cancers in number and medical experts predict that if the current trend continues, these oral cancers will move to first place. More than 50 percent of the cases are caused by HPV 16.
According to the Centers for Disease Control and Prevention (CDC) almost 12,000 new cases are confirmed each year, and men bear the brunt of the illness at 80 percent of the diagnoses. The rate of occurrence in white and black males is similar, according to the latest CDC data.
Although the statistics are clear, the reasons for the uptick are less so. Haddad agrees. “It is difficult to pinpoint the reason for increased incidence of oral cancer,” he said.
Some clinicians blame oral sex. A 2012 CDC report on the prevalence of oral sex found that roughly two-thirds of males and females aged 15-24 had engaged in oral sex, and cited birth control as a reason. Indeed, non-coital sex prevents pregnancy, but not sexually transmitted diseases.
Even more puzzling is the description of patients diagnosed with throat cancer. The typical patient is now a non-smoker and non-drinker male in his mid- 40s or early 50s. At one time, oral cancers were more commonly attributed to heavy smoking, especially when combined with heavy drinking. Victims were generally in their 60s.
There are no FDA-approved tests to detect HPV infections in men. Nor are there screening methods similar to Pap smears to find cell changes caused by HPV infections of the throat, but that does not mean one should not be vigilant. There are tell-tale signs. A sore throat and difficulty swallowing are two of them. A lump in the neck or enlarged tonsils is another. “The lump should bring you into the doctor’s office right away,” cautioned Haddad.
Doctors often rely on dental hygienists and dentists to spot the problem. “They are in a unique position to examine the mouth,” Haddad explained. “We rely on them to be the first line of detection.”
Prevention is key. “We talk about not smoking and drinking to prevent oral and other types of cancer,” he said. “We have to emphasize vaccination as well.”
Although there has been no research on the impact of HPV vaccination on throat cancer, Haddad argues there is little reason to believe it will not affect HPV-related oral cancer as well. Yet the vaccination rate, especially among males, is very low. “Many parents think this is taboo and are uncomfortable having it done,” explained Haddad.
HPV-related throat cancer is treated by surgery, chemotherapy and radiation and depends on the stage of diagnosis. The good news is that the treatment works well. According to the American Cancer Society, oropharyngeal cancers that contain HPV DNA tend to have a better outlook than those without HPV. Still, treatment comes with long-term side effects. “The treatment is difficult and can affect speech,” Haddad explained. People have difficulty with dry mouth. Anxiety and depression are common.
“Many people will be cured, but it won’t be easy,” he warned.