(RxWiki News) Oral cancers used to be associated with alcohol and tobacco use - particularly chewing tobacco and snuff. Not anymore. Studies show another practice is putting young men at particular risk for this form of cancer.
A recent study finds that cases of oropharyngeal cancer - the most common form of oral cancer affecting the throat, tong and tonsils - are increasing dramatically due to infection with the human papillomavirus (HPV). The statistics are so startling that HPV-related oral cancers are expected to exceed cervical cancers in the coming decade.
"Men can prevent oral cancer by avoiding sex with HPV-positive partners."
The study found that oral cancers linked to HPV, especially among men, increased from just over 16 percent in the 1980s to more than 70 percent 16 years later.
According to study authors, oral cancer used to be considered one cancer. Now, it's known to be two: one that's caused by tobacco and alcohol, known as an HPV-negative cancer; and the other, an HPV-positive cancer caused by the sexually transmitted virus.
HPV-positive cancers tend to be seen younger males who engage in oral sex with multiple (more than five) partners. This form of the disease has a better survival rate than HPV-negative oral cancers caused by tobacco and alcohol.
The research team, led by Maura Gillison, M.D., Ph.D., professor of medicine at The Ohio State University Comprehensive Cancer Center in Columbus, tested 271 oral cancer tissue samples gathered from 5,775 patients.
Researchers were looking for HPV infection to determine trends. Samples were collected from 1984 and 2004 at three cancer registries in the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Residual Tissue Repositories Program.
HPV-positive cancers diagnosed from 1984 to 1989 accounted for 16.3 percent, while that number rose to 72.7 percent of oral cancers diagnosed from 2000-2004, a 225 percent increase. Meanwhile, the number of HPV-negative oral cancers dropped by 50 percent during the same time period.
Dr. Gillison says these dramatic increases may reflect changes in sexual behavior, including increased oral sex.
She noted that 90-95 percent of the HPV-positive oral cancers were caused by HPV16, the virus involved with cervical cancer, and the one vaccines - Gardasil and Cervarix - target.
Vaccines could be effective in preventing oral cancers in men, but more study is needed, according to Dr. Gillison.
This study was published online in the October 3, 2011 issue of the Journal of Clinical Oncology.