The human papillomavirus (HPV) may be to blame for the alarming increase of young adults with oropharyngeal cancer, according to researchers from Henry Ford Hospital in Detroit.
The study reveals an overall 60 percent increase from 1973 and 2009 in cancers of the base of tongue, tonsils, soft palate and pharynx in people younger than age 45.
Among Caucasians, there was a 113 percent increase, while among African-Americans the rate of these cancers declined by 52 percent during that period of time.
But compared to Caucasians and other races, the five-year survival rate remains worse for African Americans.
"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," says study lead author Farzan Siddiqui, M.D., Ph.D., director of the Head & Neck Radiation Therapy Program in the Department of Radiation Oncology at Henry Ford Hospital.
"We were interested in looking at people born during that time period and incidence of oropharyngeal cancer. 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."
The study - which examined the trends in cancers of the base of tongue, tonsils, soft palate and pharynx among people 45 years-old and younger - was presented at the 55th Annual Meeting of the American Society for Radiation Oncology (ASTRO) in Atlanta.
The American Cancer Society estimates about 36,000 people in the U.S. will get oral cavity and oropharyngeal cancers in 2013; an estimated 6,850 people will die of these cancers. Oropharyngeal cancers are more than twice as common in men as in women, and about equally common in African Americans and Caucasians.
Recent medical research has shown that HPV exposure and infection increases the risk of oropharyngeal squamous cell cancer independently of tobacco and alcohol use, two other important risk factors for the disease, according to the National Cancer Institute.
The incidence of oropharyngeal cancer has been growing in recent years due to increasing rates of HPV infection. This has been largely attributed to changes in sexual practices. Studies have shown, however, patients with HPV related head and neck cancer do have a better prognosis and survival.
For the Henry Ford study, Dr. Siddiqui and his colleagues used the SEER (Surveillance Epidemiology and End Results) database to gather information about adults younger than age 45 who had been diagnosed with invasive squamous cell oropharyngeal cancer between1973 and 2009.
Since SEER does not record HPV information, the researchers used tumor grade as a surrogate indicator of HPV infection.
Among the study group of more than 1,600 patients, 90 percent were ages 36-44 and the majority (73 percent) was Caucasian.
During the 36-year period, the majority of patients (50-65 percent) underwent surgical resection for their tumors. Patients who had both surgery and radiation therapy had the highest five-year survival rate.
"These patients have a favorable prognosis and are likely to live longer while dealing with treatment related side-effects that may impact their quality of life," notes Dr. Siddiqui.
The five-year survival for the study group was 54 percent. There was no difference in survival based on gender. African Americans, however, had significantly poor survival compared to other races.
"The predominance of oropharyngeal cancer in this age group suggests either non-sexual modes of HPV transfer at a younger age or a shortened latency period between infection and development of cancer," says Dr. Siddiqui.
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