Cervical cancer rates for young women fell after HPV vaccine was introduced, according
to a new study.
The vaccine was introduced in 2006 to prevent infections that can cause several types
of cancer including cervical. The Academy recommends routine vaccination for males
and females at ages 11-12, although the vaccine is licensed for use in those ages
Researchers set out to look at the impact of the vaccine since its introduction. They
analyzed 2001-’14 data on females ages 15-34 from the Centers for Disease Control
and Prevention National Program for Cancer Registries and the National Cancer Institute
Surveillance, Epidemiology, and End Results program.
From 2011-’14, an average of six per 1 million women ages 15-24 contracted invasive
cervical cancer, a 29% decrease compared to the four years before the vaccine was
introduced. Rates fell for both squamous cell carcinoma (SCC) and non-SCC, and there
was a sharp decline after 2009.
Among women ages 25-34, cervical cancer rates dropped 13% to 76 per 1 million, and
both SCC and non-SCC types declined. However, rates already were declining slowly
before vaccine introduction, and there was not a significant decrease afterward as
there was for younger women.
Authors said it did not appear that high-risk sexual behaviors declined, so the falling
rates can be attributed, at least partially, to HPV vaccines.
“This is important, because despite previous evidence of HPV vaccine effectiveness
against HPV infections, genital warts, and cervical lesions, it is essential to know
its effect on the target outcome, cervical cancer,” authors wrote.
Vaccine coverage has been on the rise for both young and older females. In 2013, about
55% of girls ages 13-17 years had received at least one dose of vaccine, up from 29%
in 2007. Coverage for women ages 18-34 also has increased significantly since 2007.
“With the improving coverage of HPV vaccine in adolescents in recent years, the decrease
in cervical cancer incidence is expected to be more profound among U.S. women in the
near future,” authors wrote.