The World Health Organization (WHO) and European Organization on Genital Infection and Neoplasia (EUROGIN) have
The World Health Organization (WHO) and European Organization on GenitalInfection and Neoplasia (EUROGIN) have released a joint report entitled,"Cervical Cancer Control." The report, a summary of 62 scientificpapers presented at a WHO/EUROGIN meeting held in Geneva in 1996, discussesthe various aspects of cervical cancer control and contains recommendationsfor management of cervical neoplasia, development of vaccines against humanpapillomavirus (HPV), screening programs and strategies, including Papsmears and new technologies in cervical screening.
Since 1943, when Papanicolaou and Traut proposed a new technique-thePap smear test-to detect precursors of cervical cancer in women, cytologicscreening has been one of the most successful public health measures introducedfor the prevention of cancer. Mass screening programs in which women havecervical smear tests at least once every 3 to 5 years, have proven effectivein reducing cervical cancer mortality and morbidity rates. In British Columbia(Canada) and Finland, for example, organized screening has reduced mortalityrates by up to 70%.
Cervical Cancer Screening Failures
In spite of all these achievements, the reality of the situation worldwideis discouraging. Close to half a million women develop cervical cancerannually and more than 50% of those women die. Seventy-five percent ofall cases of cervical cancer occur in the developing world, where, becauseof financial constraints, mass screening programs are still wishful thinking.
Even in many developed countries, the decline of the disease in thepast decade has been insignificant, and the impact of cytologic screeninghas been far less than expected. In fact, there seems to be a substantialnumber of cases of invasive cervical cancer occurring in patients who areregularly screened, particularly young women.
According to the report, factors that determine the success of cervicalcancer screening are:
Why cervical cancer sometimes cannot be detected through cytologic screeningmay be attributed to the large intervals (more than 5 years) between testsand the high number of false-negative results (10% to 30%).
Two principal causes for the false negatives are the poor quality ofsamples and inappropriate interpretation of results. These limitationscan be overcome through improved sampling and the introduction of automateddevices that can detect 30% to 50% more false negatives than humans can.It is essential that medical and laboratory personnel involved at all stepsof cytologic testing be adequately trained, according to the report.
"New technologies, like automation and monolayer systems shouldoptimize cervical cancer screening, reduce false-negative rates, and improvequality control," comments Dr. Joseph Monsongego of France, EUROGIN'sExecutive Secretary and gynecologist in the Institut Alfred Fournier inParis. "These new technologies could have an enormous impact on theeffectiveness of cervical cancer screening. That is why the developmentof comparative trials, including cost-benefit evaluation, should be consideredin the future."
The recognition that HPV infection is a central cause of cervical cancerby the International Agency for Research on Cancer (IARC) and WHO has pavedthe way for the design of strategies for primary prevention, by immunization,and for secondary prevention, using HPV DNA testing as a screening tool.This new molecular technique can be used after cytologic screening detectsminor cervical smear abnormalities. Colposcopy can determine the natureand extent of cervical lesions in women with abnormal smears by takingbiopsies.
"The time has come to improve strategies for cervical cancer screening.In order for cytologic screening programs to be cost-effective, they shouldcover most of the at-risk female population and be initiated only whentheir quality at all levels, including sampling and interpretation of results,has been ensured," said Dr. Mark Tsechkovski, Director of the WHODivision of Non-communicable Diseases in Geneva.
For further information, contact Igor Rozov, Health Communications andPublic Relations, WHO, Geneva; tel, 4122-791-25-32, fax, 4122-791-48-58.