Newsletter
CALGARY, Alberta, Canada: The findings of a new study have shown that the incidence of cancers associated with the human papillomavirus (HPV), particularly cancers of the oropharynx, has increased in the Canadian province of Alberta over the last decades. Among other aspects, the researchers found that the increase in the incidence of oropharyngeal cancer in men was particularly high in young men.
In order to identify patients with cancers of the oropharynx and other types of cancer associated with HPV, researchers at the University of Calgary consulted the Alberta Cancer Registry, a registry of all cancers diagnosed in the province between January 1975 and December 2009.
They found that 8,120 HPV-associated cancers had been diagnosed in Alberta over the 35-year period. Oropharyngeal cancers accounted for about 18 percent of the cases. Although the highest number of cases was seen in the 55–74 age group, the greatest percentage increase in oropharyngeal cancer was seen in patients younger than 45. For this type of cancer, the increase in incidence in men was twice as high as in women.
"The increase is disturbing, because there are no screening programs for early detection of these cancers," said Dr. Lorraine Shack, lead author and adjunct assistant professor at the university's Department of Oncology. "To have a large impact on the prevention of these HPV-associated cancers, vaccination programs should be considered for males as well as females, as has now been done in Alberta."
Currently, the publicly funded HPV vaccine program in Alberta only offers vaccines to grade five girls, but the program will be expanded to boys in the same age group (as well as to grade nine boys for four years after the program begins ) from September this year.
Similar trends in the incidence of HPV-related oral cancers have been confirmed by a number of other studies. For instance, a U.S. study published in November last year found that rates of this type of cancer had increased significantly between 1983 and 2002 worldwide. Among men and those under the age of 60 in particular, oropharyngeal cancer incidence increased the most.
According to the U.S. National Cancer Institute, HPV infections are the most common sexually transmitted infections in the U.S. More than half of sexually active people are infected with one or more HPV types at some point in their lives.
The study, titled "Trends in the Incidence of Human Papillomavirus–Related Noncervical and Cervical Cancers in Alberta, Canada: A Population-Based Study," was published on July 22 in the CMAJ Open journal.
