ICO Monograph Series on HPV and Cervical Cancer: Latin America and the Caribbean Regional ReportIntegration of Human Papillomavirus Vaccination and Cervical Cancer Screening in Latin America and the Caribbean
Introduction
The recognition that infection with certain human papillomavirus (HPV) types is a necessary cause of cervical cancer has opened new fronts for the prevention of this disease. Primary prevention is now possible through immunization with highly efficacious prophylactic HPV vaccines and secondary prevention has gained momentum with the introduction of sensitive HPV DNA testing to improve traditional Papanicolaou (Pap) cytology screening programs. There has been strong endorsement by the Pan American Health Organization (PAHO) for the implementation of HPV vaccination in the Latin America and the Caribbean (LAC) region [1]. It is clear, however, that cervical cancer screening will have to continue after vaccination but as summarized in this chapter, screening programs in the region must be urgently revisited, not only from a structural and delivery standpoint but also from the perspective of the adequacy of the current testing paradigm of Pap cytology.
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Burden of disease beyond statistics
The LAC regions include some of the highest risk areas for cervical cancer in the world. Haiti was listed in the GLOBOCAN 2002 compilation of cancer incidence as the highest recorded rate at 87.3 new cases per 100,000 women annually, age-adjusted to the world population standard of 1960 [2], [3]. Ranges of age-adjusted incidence rates were 8.8–87.3 for the Caribbean, 21.6–52.4 for Central America, and 18.8–55.0 for South America (per 100,000 women annually) [2], [3]. Bahamas, Puerto Rico (a USA
Adequacy of the health care infrastructure in the region and perceived deficiencies
Before considering the opportunities for an integrated system that combines primary (HPV vaccination) with secondary (screening) prevention for cervical cancer, we must examine the experience of LAC countries in deploying these two preventive approaches independently. While HPV vaccination is a novel technology yet to be tested for large-scale implementation, cervical cancer screening has existed for decades as a separate cancer control activity. Immunization practices have also had a long
HPV vaccination
The first prophylactic HPV vaccine (Gardasil®, Merck & Co., Inc., Whitehouse Station, NJ USA) to pass regulatory approval and reach the market in most LAC countries targets four HPV types: −6 and 11, which cause most cases of genital and oral condylomata, and −16 and 18, which are the two most important oncogenic types in terms of etiologic fraction in cervical cancer. A second vaccine (Cervarix™, GlaxoSmithKline Biologicals, Rixensart, Belgium), targets the latter two types only and has just
Proposal for integrated vaccination and screening programs
A strategy that fulfills the dual mission of primary and secondary cervical cancer prevention encompasses the following arguments: 1) HPV vaccination is more effective and equitable when deployed as universal policy; 2) over time, HPV vaccination will have a negative impact on the performance of cytology, thus further straining the credibility of this test if it continues to be the cancer screening paradigm in the LAC region; 3) HPV DNA testing has the performance characteristics that make it a
Conclusions
A disproportionately high burden of cervical cancer consequent to the failure of multiple components of cervical cancer screening makes the case for universal HPV vaccination of young adolescent women a priority for the LAC region. We argued that implementation of the latter requires a critical rethinking of existing cervical cancer control policies to correct the historical shortcomings of cytology screening and to take advantage of the opportunity to adopt a strategy that synergistically
Disclosed potential conflicts of interest
EF: Advisory Board (GenProbe Inc., GlaxoSmithKline, Roche); Research Grants (Merck & Co., Inc).
AH: Research Grants (GlaxoSmithKline).
NM: Advisory Board (Merck & Co., Inc. and Sanofi-Pasteur MSD); Speakers Bureau (Sanofi-Pasteur MSD); Steering Committee (Merck & Co., Inc.).
Acknowledgements
The authors are indebted to Irma Alfaro (Qiagen) and Kathleen Menzel (Roche) for market and regulatory information on HPV tests, and to Hugues Bogaerts and Dirk Campens (GlaxoSmithKline Biologicals) and James Mansi (Merck & Co.) for the same information on HPV vaccines in LAC countries.
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