U.S. Cancer Rates Fall Overall, but Some HPV-associated Cancers Rise

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Deaths due to all types of cancer combined decreased for men and women of all racial/ethnic groups in the U.S., according to a joint "Annual Report to the Nation," published in the January 7, 2013, advance edition of the Journal of the National Cancer Institute. Incidence of oral and anal cancer increased, however, leading the report authors to call for wider use of human papillomavirus (HPV) vaccines.

The annual reportwas jointly compiled by the American Cancer Society, Centers for Disease Control and Prevention (CDC), National Cancer Institute (NCI), and North American Association of Central Cancer Registries (NAACCR). Covering the period 1975 through 2009, it provides updated figures on cancer incidence (new cases) and death rates, as well as trends in these outcomes.

Cancer incidence data were collected from the CDC, NCI, and NAACCR, while mortality data were obtained from the CDC. The report authors calculated long-term (1975-2009) and short-term (2000-2009) trends in incidence and death rates for all cancers combined, and for the major types of cancers among men and women, adjusted for age.

This year's report featured an emphasis on cancers caused by HPV, including incidence trends and HPV vaccination. Information about HPV vaccine coverage in 2008 and 2010 and of Pap testing during 2010 were obtained from national surveys.

Results

"The overall trends in declining cancer death rates continue," the report authors concluded. "However, increases in incidence rates for some HPV-associated cancers and low vaccination coverage among adolescents underscore the need for additional prevention efforts for HPV-associated cancers, including efforts to increase vaccination coverage."

In their discussion they explained that factors contributing to favorable trends in cancer mortality include reduced smoking and improved early detection and treatment. The reasons for the increasing death rates for liver, pancreas, and uterine cancer and melanoma "have not been fully elucidated." However, people who contracted hepatitis C during the 1960s-1980s have been infected long enough to develop liver cancer. Increasing obesity may contribute to liver, pancreas, and uterine cancer -- which have shown rising incidence as well as mortality -- as well as kidney cancer.

The authors noted that while overall breast cancer incidence stabilized during 2005-2009 after sharply decreasing between 2002 and 2003 -- likely thanks to reduced use of post-menopausal hormone replacement therapy -- incidence rates increased among black and Asian/Pacific islander women over the 2000-2009 time span.

"The continuing drop in cancer mortality over the past two decades is reason to cheer," said John R. Seffrin, PhD, chief executive officer of the American Cancer Society. "The challenge we now face is how to continue those gains in the face of new obstacles, like obesity and HPV infections. We must face these hurdles head on, without distraction, and without delay, by expanding access to proven strategies to prevent and control cancer."

Turning to HPV-related cancers, the proportion of mouth/throat cancer cases associated with HPV increased from 16% during 1984-1989 to 72% during 2000-2004 -- but only among white men and women -- even as tobacco-related oropharynx cancer declined in conjunction with decreased cigarette smoking. Increased rates of HPV-associated oral cancer have also been reported in Canada and several European countries.

HPV-related anal cancer incidence more than doubled between 1975 and 2009, with a higher overall burden among women than men. Rates have increased among men who have sex with men, however, largely driven by the AIDS epidemic and the high rate among HIV positive men. In contrast, cervical cancer incidence has continued to decline among women of most racial/ethnic groups thanks to wider use of Pap tests and successful treatment of precancerous lesions. Racial disparities in cervical cancer rates "may persist due to differences in screening, follow-up, and treatment of abnormal lesions," the authors wrote.

In 2006 the Advisory Committee on Immunization Practices recommended routine HPV vaccination for girls and young women age 11 to 26 years, a recommendation that was extended to boys and young men in 2011. But as of 2010, less than half (49%) of girls aged 13 to 17 years had received 1 or more doses of vaccine and just 32% had received the entire 3-dose series. Growing vaccine coverage among boys will likely improve the overall "herd immunity" against HPV, and "could eventually curb the growing burden of anal cancers, especially among men who have sex with men, and possibly the burden of oropharyngeal cancers," according to the report.

"This year’s Report correctly and usefully emphasizes the importance of HPV infection as a cause of the growing number of cancers of the mouth and throat, the anus, and the vulva, as well as cancers of the uterine cervix, and the availability of vaccines against the major cancer-causing strains of HPV." said NCI director Harold Varmus, MD. "But the investments we have made in HPV research to establish these relationships and to develop effective and safe vaccines against HPV will have the expected payoffs only if vaccination rates for girls and boys improve markedly."

The full Annual Report to the Nation is available for free online. The NCI has also prepared an overview of Frequently Asked Questions about the report.

1/15/13

References

A Jemal, EP Simard, C Dorrell, et al. Annual Report to the Nation on the Status of Cancer, 1975-2009, Featuring the Burden and Trends in Human Papillomavirus (HPV)-Associated Cancers and HPV Vaccination Coverage Levels. Journal of the National Cancer Institute. January 7, 2013 (Epub ahead of print).

M Brisson, M Drolet, and T Malagon. Inequalities in Human Papillomavirus (HPV)–Associated Cancers: Implications for the Success of HPV Vaccination. Journal of the National Cancer Institute. January 7, 2013 (Epub ahead of print).

Other Sources

American Cancer Society. Report to the Nation Shows U.S. Cancer Death Rates Continue to Drop; Special Feature Highlights Trends in HPV-associated Cancers and HPV Vaccination Coverage Levels. Press release. January 7, 2013.

HPV-associated Cancer Incidence Rates Point to Needed Efforts to Increase HPV Vaccination Coverage. Press release. January 7, 2013.