[Prevention of cervical cancer (II): prophylactic HPV vaccination, current knowledge, practical procedures and new issues].
Despite the considerable success of early screening for prevention of cervical cancer, Pap smears have not fulfilled the hopes that it would lead to a large-scale reduction of this cancer's incidence. Screening appears to be useful for a tiny portion of the world population, although a relatively large portion must put up with its limitations and disadvantages. Human papilloma viruses (HPV) 16 and 18 are responsible for two thirds of all cervical cancers worldwide. The condylomata (condyloma acuminatum), or genital warts, induced by HPV 6 and 11 are frequent among the young and difficult to manage. The extent and burden of HPV infection are considerable, as is the psychological and emotional impact of the diseases associated with it. Because cancer of the cervix is the final consequence of chronic HPV infection, it can be prevented by vaccination. A prophylactic vaccine to protect against the precancerous and cancerous lesions associated with HPV should save lives, reduce expensive diagnostic and therapeutic interventions, and have substantial individual and collective benefits. Clinical trials of anti-HPV vaccines for the prevention of cervical cancer and condyloma have shown remarkable results and an efficacy unequaled in the history of vaccination against infectious diseases. Vaccine efficacy has been shown only in young girls never exposed to the virus and only for the lesions associated with the specific viral types in the vaccine. Preliminary data indicate that the vaccination is effective in women who have previously eliminated naturally the virus. It has no therapeutic effects on existing lesions or in healthy virus carriers. Practical questions remain to be resolved. If the vaccination is left to individual initiative and vaccination coverage is insufficient, there will be no perceptible reduction in the frequency of cervical cancer. Vaccination policies will not be identical in poor countries, where the disease represents one of the leading causes of mortality among women, and in the rich countries, where screening programs have considerably reduced the frequency of this cancer. Current planning calls for the introduction of systematic vaccination of young girls aged 9-15 years, with progressive "catch-up" vaccination of the cohorts of young women aged 16-26 years. Nonetheless mathematical models and immunogenicity results indicate a possible benefit for individual vaccination of adults. This approach must still be assessed in the clinical trials underway. Because the vaccine does not protect against all types of HPV associated with cervical cancer, screening must be continued according to the conditions currently set. Vaccination and screening, which are complementary and synergistic, now constitute the new standards for prevention of this disease.
Monsonego
Joseph
J
Institut Alfred Fournier, Paris. jmonsonego@wanadoo.fr
D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D030361:Papillomavirus Infections / Q000150:complications / Q000517:prevention & control*; D053918:Papillomavirus Vaccines; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology
D053918:Papillomavirus Vaccines