This article is more than 5 years old. Information may no longer be current.
Incidence of HPV-positive oropharyngeal squamous cell carcinoma on the rise
Ramqvist T. Emerg Infect Dis. 2010;doi:10.3201/eid1611.100452.
Click Here to Manage Email Alerts
A growing proportion of human papillomavirus-positive oropharyngeal squamous cell carcinoma cases may be attributable to increased sexual transmission of the disease, recent study data indicate.
“During the past few decades, HPV DNA has been detected in about 25% of [head and neck squamous cell carcinomas] overall, but especially in [oropharyngeal squamous cell carcinoma], for which 45%-100% cases were reported to be HPV positive,” wrote researchers from the Karolinska Institutet in Stockholm and the Swedish Institute for Infectious Disease Control in Solna.
To investigate the relationship between HPV and these cancers, the researchers analyzed data from the Swedish Cancer Registry collected between 1970 and 2002 in the Stockholm area. Results suggested a 2.9-fold increase in the number of HPV-positive tonsillar cancer, from 23% to 68%, among all 237 samples taken from the 515 patients with the disease.
In a second study, the researchers conducted follow-up on the incidence of HPV in tonsillar cancer from 2003 to 2007. Data indicated that the number of HPV-positive cancers increased from 1970 to 2007 (P<.0001) and 2000 to 2007 (P<.01). Additionally, from 2006 to 2007, 93% of tonsillar cancer was HPV-positive, and incidence of HPV-positive tumors nearly doubled with each decade during the study period. The incidence of HPV-negative tumors, however, decreased.
Similarly, the prevalence of HPV-positive base of tongue cancer rose from 1998 to 2007, demonstrating an increase of 54% from 1998 to 1999 and 84% from 2006 to 2007.
“The possible causes for this increase have been discussed extensively and have focused on changes in sexual patterns, such as increased oral sex or increasing numbers of sex partners,” the researchers wrote. “A significant association has been shown between HPV-positive tonsillar cancer and early initial sex or number of oral or vaginal sex partners.”
The researchers said one study from the United States also linked open-mouthed kissing with HPV infection and noted that these findings could significantly affect the timing of prophylactic vaccination of children.
“We suggest that we are encountering a slow epidemic of mainly sexually transmitted HPV-induced [oropharyngeal squamous cell carcinoma],” they wrote.
Studies examining factors in treating HPV-positive cancers are conflicting, and the researchers said additional information is needed. “Future prospective clinical studies, including diagnostics of HPV, molecular and immunologic profiles, history of smoking, cessation of smoking during therapy, and effects of different treatment modalities and their side effects on quality of life, will be of benefit for personalized treatment,” they said.
Further monitoring of vaccination’s effect on HPV-positive cancers is also important, the researchers concluded.