Cancer Control Opportunities in Low- and Middle-Income Countries (2007) / Chapter Skim
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6 Compelling Opportunities in Global Cancer Control
6 Compelling Opportunities in Global Cancer Control
Pages 170-224
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From page 170... ...
They are: · Increased coverage with hepatitis B virus (HBV) vaccine to prevent most liver cancer globally · Cervical cancer prevention through cost-effective screening and treatment, and planning for the expeditious adoption of human papillomavirus 0
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The reasons are detailed in the first section of this chapter. This is the most straightforward and obvious cancer control intervention that requires added support from the global community.
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From page 172... ...
HCV vaccine development is ongoing and, if successful, would provide a way to prevent another part of the liver cancer burden. Where HBV is widespread, babies may be infected perinatally by their mothers in the period shortly before and after birth, or during early childhood from contact with other children.
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From page 173... ...
For people already infected, reducing exposure to aflatoxin or modifying its effect through diet and reducing excessive alcohol consumption can help. HBV Vaccination An HBV vaccine suitable for widespread public use has been available for more than 20 years.
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Where transmission is less intense, all three doses can be given along with the other routine childhood vaccines. The United States, a low-endemicity country, adopted universal infant vaccination in 1991, supplemented with targeted vaccinations for older children and adults at highest risk of infection.
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At discount rates lower than 4 percent, universal infant immunization would be cost saving for the health care system, and at rates lower than 6.3 percent, it would be cost saving to society. How Many Deaths Could Be Preented with HBV Vaccination?
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In 1992, WHO recommended that all countries with a high hepatitis B disease burden introduce HBV vaccine into their routine immunization programs by 1995, and that all countries do so by 1997. These targets were not met, however.
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The GAVI partners set a new milestone, which is for HBV vaccine to be introduced in all countries with adequate delivery systems by 2007. Childhood HBV vaccination has now been adopted by many countries, but there is still a wide gap between rich and poor countries.
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Can More Be Done to Increase HBV Vaccine Coerage? The global community can continue to encourage countries to include HBV vaccination with their childhood immunization programs, and particularly in high-prevalence countries, to start with a birth dose.
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From page 179... ...
cells on the surface of the cervix, which can be removed using relatively simple, minimally invasive procedures. The more detailed understanding of how cervical cancer develops, and the role of HPV, has led to new screening and treatment approaches, as well as the development of vaccines to protect against HPV infection, one of which just entered the market in 2006.
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From page 180... ...
The risk of acquiring HPV increases with the number of sexual partners and with early age at first sexual activity (IARC Working Group, 2005)
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HPV Types and Their Association with Cerical Cancer Only a handful of the 100 known types of human papillomaviruses are associated with a high risk of cervical cancer (IARC Working Group, 2005)
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. Natural History of HPV and Cerical Cancer In 1908, Schanenstein proposed the idea that invasive cervical cancer develops only after progressing through preinvasive lesions (Chirenje, 2004)
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. About half of women with CIN 3 lesions will progress to invasive cervical cancer if not treated (<1 percent of all original HPV infections)
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cellular changes. The Pap smear and related laboratory examination of cells (cytology)
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From page 185... ...
Each major screening approach is described briefly in the next sections. Pap Smear and Cerical Cytology "Conventional cervical cytology"1 is the process of collecting cell specimens from two areas of the cervix: the transformation zone, using a specially shaped wooden or plastic spatula; and the endocervix (endocervical canal)
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From page 186... ...
Visual inspection with acetic acid (VIA) In VIA dilute acetic acid (vinegar)
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Pap Smears and Cytology The accuracy of Pap smears and cytology based on recent work was reviewed in 2005 (IARC Working Group, 2005) and is summarized in Table 6-6.
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Visual inspection methods have had similar or better sensitivity than cytology for detecting CIN 2 or 3 or invasive cancer in most studies, but
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The sensitivity of VIA to detect high-grade precancerous lesions and invasive cervical cancer varied widely, from 29 to 95 percent, and specificity varied from 68 to 98 percent (IARC Working Group, 2005)
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. Comparing Testing Methods Accuracy HPV testing and the visual inspection methods are more sensitive than Pap smears and cytology at a single screening, at least under study conditions.
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HPV testing and Pap smear require laboratory facilities or transport systems to take samples to a laboratory, and a stable supply of electricity, while visual inspection techniques do not. In addition to these requirements is the need to make arrangements for treating conditions detected, from precancerous conditions to invasive cancer.
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. Cervical Cancer Prevention Implementation Experience with Pap Smear and Cytology Programs By the 1960s, Pap smears were available in many developed countries from physicians on a case-by-case basis.
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and basic health care needs are not being met, visual inspection programs may be more feasible than Pap smear-based programs. This reality is the driver behind efforts to determine the value and feasibility of alternative screening methods.
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The effect of a single screening, at age 35, was greatest with HPV one- and two-visit screening (30 to 36 percent reduction in lifetime cervical cancer risk) , followed by one- and two-visit visual inspection (25 to 31 percent reduction)
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Characteristics of Screening Tests VIA Sensitivityb 76 6090 Specificity 81 6696 HPV DNA Sensitivityb 88 6595 Specificity 93 7096 Cytology (Pap smear) Sensitivityb 63 4585 Specificity 94 8098 Characteristics of Screening Program Participationc 100 25100 Loss to follow-up (per visit)
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Among the strategies, single-visit visual inspection was the least expensive and threevisit Pap smear cytology the most expensive. For every strategy, most of the cost was attributable to cancer treatment, so additional screenings tended to raise costs only minimally.
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. Merck's vaccine, GARDASIL®, was approved by the FDA in June 2006, based on clinical trials that included about 21,000 women and 4,000 men around the world.
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A $12.9 million grant from the Bill and Melinda Gates Foundation was recently awarded to WHO, IARC, the Program on Appropriate Technology for Health (PATH) , and Harvard University toward a collaborative effort to bring HPV vaccines to developing countries.
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The numbers of childhood cancers and deaths (below age 15) are modest in the poorest countries, and low compared with the corresponding figures for cancer in adults.
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00 CANCER CONTROL OPPORTUNITIES Thailand Ukraine Mauritius Kazakhstan France Cuba Brazil 0 5 10 15 20 25 Infection Cancer FIGURE 6-1 Number of registered deaths per 100,000 among ages 124 years, selected countries, in 2000. SOURCE: Personal communication, I
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From page 201... ...
But children are also a compelling focus for the reasons given: assured success for a large number if given appropriate treatment, which can be relatively uncomplicated and relatively inexpensive; living cancer survivors; and some development of cancer treatment infrastructure that forms a core for expanded services. Differences Between Childhood and Adult Cancers The cancers that arise in children are, by and large, different from cancers of adults, everywhere in the world.
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. Patterns of Childhood Cancer in Less and More Developed Countries While leukemias and lymphomas comprise about 4050 percent of all new cases of cancer in children worldwide, the frequencies of other cancers -- and of the specific types of leukemias and lymphomas -- have distinct geographic distributions.
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As is true for adult cancers, no traditional treatments are known to be effective against childhood cancers. In addition to the purely economic and practical constraints, social and psychological support for children and families going through the arduous and prolonged process of cancer treatment is limited.
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One feature of childhood cancer treatment in the United States and other high-income countries is worth emulating: the highly collaborative and cooperative character of the pediatric oncology community. Since the 1960s, when treatments began to make a real difference in the survival of children with cancer, the majority of pediatric oncologists and their patients have participated in clinical trials, and patients have benefited.
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In addition, the International Network for Cancer Treatment and Research (INCTR) has established networks of various types around several childhood cancers: acute lymphocytic leukemia, retinoblastoma (Box 6-2)
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a worldwide mobilization and awareness campaign to highlight the effects of childhood cancers; and (3) a comprehensive report on childhood cancers, which was released on World Cancer Day, February 4, 2006 (International Union Against Cancer, 2006)
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. Improving Childhood Cancer Treatment in LMCs Children with cancer in LMCs can be treated and cured -- and appropriate psychosocial and family support provided -- under conditions that are feasible even in resource-poor settings.
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3. A PCU is part of, or linked to, a national and/or international multidisci plinary organization for pediatric oncology, in order to facilitate communica tion and coordination of new treatment methods and research.
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These specialists ensure a round-the-clock service, recruit new PCU personnel, and provide adequate training in pediatric oncology. A PCU comprises the following facilities: A ward for in-patients sufficiently staffed and equipped (including proper isolation facilities)
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The stated objective from the beginning was to begin "a comprehensive, long term program to establish a national PCU capable of offering a reasonable possibility of cure to Nicaraguan children with cancer." Staff development La Mascota initially had no staff with training in pediatric oncology. From the beginning, pediatricians, and later nurses and other specialists (urologists, nephrologists, pulmonologists, surgeons, laboratory scientists)
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St. Jude Children's Research Hospital International Outreach Program St.
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Ecuador: Quito Centro Médico Meditropoli Foundation SOLCA: La Sociedad de Lucha Control el Cancer El Salvador: San Hospital de Niños Benjamín Bloom Fundacion Ayudame a Vivir Salvador Guatemala: Unidad Nacional de Oncologia Fundacion Ayudame a Vivir Guatemala City Pediatrica, Hospital Roosevelt Honduras: Hospital Escuela Bloque Materno Fundacion Hondureña Para El Tegucigalpa Infantil, Hospital Viera Niño con Cancer Jordan: Amman King Hussein Cancer Centre King Hussein Cancer Foundation Lebanon: Beirut The Children's Cancer Center of The Children's Cancer Center of Lebanon, Faculty of Medicine Lebanon and Medical Center, American University of Beirut Mexico: Sinaloa Hospital Pediatrico de Sinaloa, Amigos de Niños Afectados de Culiacan Cancer A.C. Mexico: Hospital Civil de Guadalajara Guadalajara Morocco: Rabat Hospital d'Enfants Rabat-Maroc de L'Avenir, Association des Parents et Amis de Enfants Morocco: Hospital 20 Aout 1953 Agir, Association Marocaine de Casablanca Soutien Russia: Moscow Research Institute of Pediatric Hematology Venezuela: Hospital de Ninos J.M.
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From page 213... ...
Regional Initiaties in Latin America With the network of partners having grown in a number of countries, the IOP has developed more regional programs, including workshops for medical professionals and fundraisers. A Central American Pediatric Oncology Infrastructure Program has also been proposed through the Association
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The foundations typically develop and support: · Care, treatment, and psychosocial support of patients · Salaries and training for key personnel · Construction and renovation of facilities · Efforts to increase government support for childhood cancer treatment · Activities to raise public awareness that childhood cancers are curable at early stages The 19 foundations affiliated with IOP partners have raised a total of $12.5 million over the past several years through donations and by soliciting funds from grant-making organizations. These funds have been used to provide housing for patients and families at or near the hospitals, to support salaries of key personnel, and to pay for medications.
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. Improving the Quality of Pediatric Cancer Treatment Through Clinical Trials and Centers of Excellence By the early 1980s, major advances had already raised long-term survival from ALL in the United States and Europe to 70 percent.
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In the process, three centers of excellence for pediatric cancer have been developed in India that form a strong nucleus for expanding treatment to other centers. Examples of centers of excellence improving the success of pediatric cancer treatment can be found elsewhere.
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Doing so will build cancer management capacity more generally, and if done properly, will result in a rare class in many LMCs -- cancer survivors, whose survival belies an alltoo-common belief that cancer is inevitably fatal. Experience has shown that childhood cancer treatment can be financed through a combination of local and foreign sources in countries where it has been seriously attempted.
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2003. Cofactors in human papillomavirus carcinogenesis -- role of parity, oral contraceptives, and tobacco smoking.
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2003. Visual Inspection of the Uterine Cerix with Acetic Acid (VIA)
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2002. A controlled trial of a human papillomavirus type 16 vaccine.
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1998. The natural history of human papillomavirus infection as measured by repeated DNA testing in adolescent and young women.
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1998. Visual inspection of the uterine cervix after the ap plication of acetic acid in the detection of cervical carcinoma and its precursors.
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Risk factors for invasive cervical carcinomas with human papillomavirus types 16 and 18 DNA. American Journal of Epidemiology 153(8)
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2005. Prophy lactic quadrivalent human papillomavirus (types 6, 11, 16, and 18)
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