HPV-Linked Cancers Persist, Says CDC

Cancers associated with human papillomavirus (HPV) continue to exact a considerable burden, particularly among women, a CDC report suggested.

This oncogenic virus causes almost all cervical cancers and has been linked with many other anogenital cancers.

Each year between 2004 and 2008, roughly 33,370 cases of cancer possibly associated with HPV were diagnosed in the U.S., at a rate of 10.8 per 100,000 population.

These included 21,290 cancers among women and 12,080 in men, for respective rates of 13.2 and 8.1 per 100,000.

“Multiplying the counts for HPV-associated cancers by percentages attributable to HPV, CDC estimated that approximately 26,000 new cancers attributable to HPV occurred each year, including 18,000 among females and 8,000 among males,” the agency reported.

These data emerged from analyses of data from the National Program of Cancer Registries and the Surveillance, Epidemiology, and End Results (SEER) database, which includes the entire U.S. population.

The researchers gathered data on cancers of the cervix, vulva, vagina, penis, anus, and oropharynx - locations where HPV DNA often can be detected.

They reported that cervical cancer topped the list, with 11,967 cases occurring each year, followed by cancer of the oropharynx, with 9,356 cases in men and 2,370 in women.

Women had higher rates of anal cancer, at 1.8 per 100,000, compared with 1.2 per 100,000 for men. But men had four times the rate of oropharyngeal cancer (6.2 versus 1.4 per 100,000), according to the CDC.

Hispanics had rates of penile and cervical cancer of 11.3 per 100,000, while the rates among blacks and whites were 9.9 and 7.4 per 100,000, respectively.

Rates of vulvar cancer were highest for white women, at 1.9 per 100,000, compared with 1.4 and 1.2 per 100,000 in blacks and Hispanics.

Differences in overall HPV-associated cancers also were seen by state, with Utah having the lowest rates, which were 8.5 and 4.9 per 100,000 among women and men, respectively.

Among women, the highest rates were found in West Virginia, at 16.3 per 100,000, while the District of Columbia was highest for men, with 11.6 per 100,000.

For the individual cancers, the number and percentages attributable to HPV were:

  Cervix, 11,500 (96%)
  Vulva, 1,600 (51%)
  Vagina, 500 (64%)
  Penis, 400 (36%)
  Anus (women), 2,900 (93%)
  Anus (men), 1,600 (93%)
  Oropharynx (women) 1,500 (63%)
  Oropharynx (men), 5,900 (63%)

However, these numbers do not reflect actual HPV infections and are only estimates, according to the report.

In an editorial note, the agency noted that many of these cancers can be prevented by the two available HPV vaccines. The Advisory Committee on Immunization Practices currently recommends that girls be vaccinated at age 11 or 12, providing three doses of either the bivalent or quadrivalent vaccine.

Since December 2010 the committee has also recommended that boys receive three doses of the quadrivalent vaccine at age 11 or 12.

Secondary prevention of cervical cancer through Pap testing also is recommended, although at less frequent intervals. While the overall rate of screening exceeds 80%, variations are seen among minorities.

“If smaller percentages of adolescent girls in the same demographic groups receive HPV vaccine, disparities in cervical cancers might increase,” the agency cautioned.

The analysis had limitations, the authors noted, including a lack of information on actual HPV infection and risk factors including cigarette use, and the unavailability of more recent data.

“Ongoing surveillance of HPV-associated cancers using high-quality population-based registries is needed to monitor trends in cancer incidence that might result from increasing use of HPV vaccines, changes in cervical cancer screening practices, and changes in behaviors that increase risk for HPV infection, persistence, or progression,” they concluded.

Most of the authors are employees of the CDC.

Primary source: Morbidity and Mortality Weekly Report
Source reference: Wu X, et al “Human papillomavirus-associated cancers - United States, 2004-2008” MMWR 2012; 61: 258-261.

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