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, which examined the trends in cancers of the base of the tongue, tonsils, soft palate, and pharynx among people 45 years old and younger, was presented at this week's American Society for Radiation Oncology annual meeting, held September 22-25 in Atlanta.
The study revealed an overall 60% increase from 1973 and 2009 in cancers of the base of the tongue, tonsils, soft palate, and pharynx in this demographic.
Among Caucasians, there was a 113% increase, while among African-Americans the rate of these cancers declined by 52% during that time period. But compared with 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," lead author Farzan Siddiqui, MD, PhD, the director of the head and neck radiation therapy program at Henry Ford in a news release. "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."
Dr. Siddiqui and his colleagues used the Surveillance, Epidemiology, and End Results (SEER) database to gather information about adults younger than age 45 who had been diagnosed with invasive squamous cell oropharyngeal cancer between 1973 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% were ages 36 to 44 and the majority, 73%, was Caucasian.
During the 36-year period, 50% to 65% of patients 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," Dr. Siddiqui noted.
The five-year survival for the study group was 54%. There was no difference in survival based on gender. African-Americans, however, had significantly poor survival compared with other races. "The predominance of oropharyngeal cancer in this age group suggests either nonsexual modes of HPV transfer at a younger age or a shortened latency period between infection and development of cancer," Dr. Siddiqui said.
The American Cancer Society estimates about 36,000 people in the U.S. will get oral cavity and oropharyngeal cancers in 2013, and an estimated 6,850 people will die of these cancers. 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.