The rate of oropharyngeal cancer has gone up significantly among young adults over the last 35 years, according to a new study -- an increase that may be caused, at least in part, by the most common sexually transmitted infection, human papillomavirus.
Oropharyngeal cancers include cancers of the base of the tongue, pharynx (throat), soft palate and tonsils. Researchers found that the rate of these cancers increased 60 percent between 1973 and 2009 among people under age 45.
However, researchers found that the rate of increase differed drastically between racial groups -- oropharyngeal cancers increased 113 percent for white people, while it actually decreased by 52 percent for African Americans.
"Not only were we surprised to find a substantial increase in young adults with cancer of the tonsils and base of tongue, but also a wide deviation among Caucasians and African Americans with this cancer," study researcher Dr. Farzan Siddiqui, M.D., Ph.D., director of the Head & Neck Radiation Therapy Program in Henry Ford Hospital's radiation oncology department, said in a statement.
The findings were presented at the annual meeting of the American Society for Radiation Oncology. For the study, researchers analyzed data from the Surveillance Epidemiology and End Results (SEER) database, of more than 1,600 adults under age 45 (majority were between 36 and 44) diagnosed between 1973 and 2009 with invasive squamous cell oropharyngeal cancer. Seventy-three percent of the people in the study were white.
Even though information on HPV status was not available for the people in the database, researchers were able to extrapolate HPV status from tumor grade.
Researchers found that the survival rate over five years for people in the study was 54 percent, with men and women having similar survival rates, but African Americans having worse survival rates than white people.
"The growing incidence in oropharyngeal cancer has been largely attributed to the sexual revolution of the 1960s and 1970s, which led to an increased transmission of high-risk HPV," Siddiqui said in the statement.
HPV is a known risk factor for both oral and throat cancers. The Mayo Clinic points out that other risk factors for throat and oral cancers include tobacco use and excessive alcohol consumption.
In addition to oropharyngeal cancers, persistent HPV infection can also cause genital warts, cervical and genital cancer, and a wart condition called recurrent respiratory papillomatosis, according to the Centers for Disease Control and Prevention.