A new report documents a disturbing rise in the number of cases of cancer related to HPV, a family of sexually transmitted viruses linked to tumors of the cervix, head and neck, and several organs.
The spike in HPV-related cancers defies the generally positive trends in cancer, whose incidence and mortality rates continue to fall slightly each year, the report says. It was published online Monday in the Journal of the National Cancer Institute.
HPV, or human papillomavirus, is best known for causing cancer of the cervix and genital warts, both of which can now be prevented by vaccines. But HPV also causes cancers of the vagina, vulva, penis and anus, as well as oral cancers involving the back of the throat, tonsils and base of the tongue.
And while cervical cancer rates have fallen dramatically because of screening tests, rates of other HPV-related cancers are increasing, probably the result of changes in sexual practices over the past 30 to 40 years. "This is one of the epidemics of the 21st century," says Otis Brawley, chief medical officer at the American Cancer Society, a co-sponsor of the report. "This is a huge problem."
About 12,200 women a year are diagnosed with cervical cancer, and 7,100 people develop HPV-related oral cancers, says the Centers for Disease Control and Prevention, another sponsor of the report. If trends continue, oral cancers will overtake cervical cancers as the leading cause of HPV-related tumors by 2020.
Overall, oral cancers have been declining as fewer Americans smoke or drink heavily, says Richard Schlegel, chairman of pathology at the Georgetown Lombardi Comprehensive Cancer Center.
The proportion of HPV-related oral tumors has increased, however, from 16% of all oral cancers in 1984 to 1989 to 72% of such tumors from 2000 to 2004, the report says.
The new HPV vaccines, which are recommended for boys and girls at ages 11 or 12, have been shown to protect against cervical, vaginal and vulvar cancers but have not been tested on oral cancers.
Still, tests on animals suggest an HPV vaccine would work for oral cancer, Schlegel says. That's because both approved vaccines block HPV 16, a subtype of the virus that causes most of of these cancers.
"If we let it," Brawley says, "the HPV vaccine may prove to be a godsend for head and neck cancers."
Yet fewer than half of American teen girls have gotten one or more doses of the HPV vaccine, and only 32% have received all three recommended shots, the report says. In comparison, more than 70% of girls in Australia and the United Kingdom have completed all three shots.
According to the report, called the Annual Report to the Nation on the Status of Cancer, the girls most likely to die of cervical cancer also are among the least likely to get an HPV shot: those who are poor, uninsured or living in economically depressed areas of the South.
The vaccines, which cost about $390 for three shots, have been marketed "to patients who can afford it, not those who need it," says Sheila Rothman of Columbia University's Mailman School of Public Health in New York. "The vaccine isn't really getting to the groups who need it."
To see more of USAToday.com, or to subscribe, go to http://www.usatoday.com
Copyright 2012 USA TODAY, a division of Gannett Co. Inc.