Two papers published in the Jan.
5 issue of the Journal of the American Medical Association (JAMA)
suggest human papillomavirus (HPV) testing is as sensitive as the Pap test
for detecting cervical cancer and high-grade precancerous changes. Experts
say HPV testing has potential value in countries that lack adequate Pap
screening services.
HPV is associated with almost all cases of cervical cancer, so scientists
have been looking into whether testing for HPV infection could be used
as a screening test for cervical precancers and early cancers. The two
JAMA studies along with an accompanying editorial address that question.
Editorial author Jack Cuzick, PhD, of the department of mathematics,
statistics, and epidemiology at the Imperial Cancer Research Fund in London,
believes the advantages of HPV testing are its simplicity – samples may
be collected by health professionals or by women in their own homes using
vaginal swabs – and its potential for use in places where women don't have
adequate access to Pap screening.
Robert Smith, PhD, director of cancer screening for the American Cancer
Society (ACS), agrees with that assessment. "Both studies showed the sensitivity
of the HPV test can approximate that of the Pap smear," Dr. Smith said.
"This means the potential for using HPV testing in countries without adequate
cervical cytology services, or as an adjunct test in countries with established
cervical cytology services, is potentially a viable option."
Disadvantages are that HPV testing produces more false positives (test
results implying a condition exists when in fact it does not) than the
Pap test and increases the cost of screening – a concern particularly in
places where Pap testing is already available. The consequence of false
positives is more women would need to undergo colposcopy (viewing the cervix
through an instrument that resembles binoculars) and biopsy (removing a
small tissue sample).
"More research is necessary to reconcile under what circumstances either
of these options would contribute to the primary goal of cervical cancer
screening, which is the prevention of invasive disease and death from cervical
cancer," Dr. Smith said.
The value of HPV testing is strongly influenced by a woman's age. HPV
infection is quite common among young women but most of these infections
eventually resolve themselves without treatment and never lead to a cancer
or even a high-grade precancer. Among women over 40, however, HPV infection
carries a greater risk of eventually leading to cancer.
The value of cervical cancer screening with the Pap test or, potentially,
with HPV testing, is precancers and early cancers found by these tests
are completely curable. The ACS recommends all women who are or have been
sexually active or who are 18 and older have an annual Pap test and pelvic
examination. After three or more consecutive negative exams, the test may
be done less often.
Unfortunately, many women in the US still do not take advantage of the
Pap test. About 70 percent of women newly diagnosed with invasive cervical
cancer had not had a Pap test within the past five years.
ACS News Center stories are provided as a source of cancer-related
news and are not intended to be used as
press releases.
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