02/02/08

UNITED STATES:  HPV Causing More Oral Cancer in Men

Human papillomavirus, the STD that is the leading cause of cervical cancer in women, could soon become one of the top causes of oral cancers in men, according to a new study.

In addition to cervical cancer, HPV can cause genital warts and increase the risk for penile and anal cancer for males. Previous research has established HPV as the primary cause of the estimated 5,600 cancers that occur annually in the tonsils, lower tongue, and upper throat - a role that has been rising over time.

In the new study, Dr. Maura Gillison of Johns Hopkins University and colleagues examined more than 30 years of National Cancer Institute data on oral cancers. They categorized approximately 46,000 cases by using a formula to divide them into those caused by HPV and those not linked to the virus.

The researchers found the incidence rate for HPV-related oral cancers increased steadily in men from 1973 to 2004, making it nearly as common as those from alcohol and tobacco. "If the current trend continues, within the next 10 years there may be more oral cancers in the United States caused by HPV than tobacco or alcohol," said Gillison.

Though studies indicate that oral sex is associated with HPV-related oral cancers, a cause-effect relationship has not been proved. Some research has suggested that unwashed hands can spread HPV to the mouth.

Sex may explain the increase in male upper throat cancers, Gillison noted. However, HPV-related upper throat cancers among women declined significantly from 1973 to 2004.

Merck & Co. makes the only HPV vaccine currently available in the United States; it is now given only to girls and young women. Merck plans to seek Food and Drug Administration approval for use in boys later this year, primarily to prevent males from spreading HPV and help reduce the almost 12,000 cervical cancer cases diagnosed in US women annually. But the study's results point out there may be a direct benefit for males too. "We need to start having a discussion about those cancers other than cervical cancer that may be affected in a positive way by the vaccine," said Gillison.

The study, "Incidence Trends for Human Papillomavirus-Related and -Unrelated Oral Squamous Cell Carcinomas in the United States," was published in the Journal of Clinical Oncology (2008;26(4):612-619).

Source: http://www.ap.org/ ::Mike Stobbe; Courtesy of the CDC National Center for HIV, STD, and TB Prevention