Beyond the Pap

Scientists haveknown for some time that virtually all cases of cervical cancer are triggeredby a family of viruses called human papillomavirus,or HPV.Most women who

become infected withHPV are able to shake off the virus and suffer no apparent long-termconsequences to their health.But a few women develop a per- sistent infectionthat

can,for reasons thatare not entirely clear,eventually lead to cancerous changes in the cervix。

Now researchers atthe Digene Corp.of Beltsville,Maryland,have developed a test that detects anac- tive HPV infection by looking for its genetic byproducts in the

vagina.The HPV testwas better than the standard Pap test at finding cervical cancer at anystage,according to two studies published this month in the Journal of theAmerican

MedicalAssociation.So far,so good.Unfortunately,the test's false-positive rate- howoften it indicated that there was a problem when none existed-was almost twiceas high as

that for the Papsmear.In these cases,a biopsy of the woman's cervix showed no sign of disease.

And that's the cruxof the problem.How many women should undergo what is,when it comes right downto it,unnecessary treatment to find a few more cases of cervical

cancer? Shouldn'thealth officials fodus instead on making sure that more women undergo regularPapsmear examinations?After all,Pap smears,though far from perfect,have

helped dramaticallylower the death toll from cervical cancer,taking it from the No.1 cause ofdeath due to cancer in American women to the 10th.

Complicating mattersis the fact that HPV is a very common infection.In some parts of the US as many ashalf of all women under age 35 have an active case.Yet 99 out of

100 women who areHPV-positive will never get cervical cancer,estimates Dr.Joanna Cain,vicepresident of the American College of Obstetriciansand Gynecologists."If

those 99 women livetheir lives as if they're going to develop cancer,"she says, "we'renot necessarily doing them any good."

At present,the HPVtest is approved in the US only to help resolve ambiguous results from aPapsmear test.Many gynecologists believe that HPV will eventually replace the

Pap.But they're notwilling to aban don it without a lot more detailed information and neithershould you.Only a few casesof HPV infection will lead to cancerous changes in the cervix.

A.Right

B.Wrong

C.Not mentioned