Unprecedented gains have been made in the cure rates for childhoodcancer during the past four decades. This progress reflectssteady improvement in treatment protocols, a multidisciplinaryapproach to patient care, adequate hospital infrastructure,and psychosocial and economic support for affected families.Perhaps the greatest success has been the 80 percent cure rateamong children with acute lymphoblastic leukemia who are treatedin a modern center. Most of these survivors have long, productivelives, are well integrated into their communities, and makesubstantial contributions to society.1 But this story of medicalachievement is tempered by the harsh reality that more than60 percent of the world's children with cancer have little orno access to effective therapy, and their survival rates arepredictably inferior to those in countries with advanced healthcare systems. The geographic inequality in cancer treatmentposes challenges that have only begun to be addressed.2,3
Perhaps the most compelling case to be made against investingin better cancer treatment for children in poor countries isthat millions of deaths may be prevented by focusing insteadon relatively inexpensive strategies for combating infectiousdiseases. Indeed, the World Health Organization and many internationalcharities have committed their resources to reducing mortalityfrom infectious diseases by two thirds during the next decade.Not surprisingly, noncommunicable diseases and chronic childhooddisorders are not among the priorities of these organizations.Although the marshaling of resources to fight infectious diseasesclearly has the potential to save the most children in developingcountries, we would argue that alternative support mechanismsare also needed to ensure wider access to effective cancer treatment.This argument is not grounded solely in humanitarian considerations;it also addresses the rapidly changing profile of causes ofillness and death among children in countries with limited resources.
Although pediatric human immunodeficiency virus infection andAIDS remain a critical health priority in sub-Saharan Africa,cancer is emerging as a major cause of childhood death in developingregions of Asia, South and Central America, northwest Africa,and the Middle East, as a result of reduced mortality from preventableinfectious diseases.3 For example, in 1960, the rate of deathamong infants in China was 150 per 1000 live births; among childrenunder five years of age, the death rate was 225 per 1000 livebirths. By 2002, the rates had decreased to 31 per 1000 and39 per 1000, respectively. As the population of Chinese childrennears 300 million, a conservative projection of 45,000 new casesof pediatric cancer each year can be made.
At the Shanghai Children's Medical Center, which serves theonly Chinese city in which health insurance for catastrophicdiseases is offered, 234 children with acute lymphoblastic leukemiawere admitted for treatment between October 1998 and June 2003.According to Dr. J.Y. Tang of the medical center, therapy for66 of these children (most of whom did not live in Shanghai)had to be abandoned, apparently for financial reasons, and another52 children died of leukemia or treatment-related complications,leaving only 116 in continuous complete remission. This problemis much worse elsewhere in the country, especially in ruralareas: only about 10 percent of Chinese children under 14 yearsof age who have acute leukemia receive protocol-based therapy,according to Dr. L.J. Gu, also of the Shanghai center.
What, if anything, can be done to bring the benefits of moderncancer treatment to more children? The most immediate and substantialresults will probably come from expanded access to treatment,the elimination of reasons for abandoning treatment, and bettercontrol of complications of infections. Possible approachesto achieving these goals are admirably covered in the recentbook Cancer in Developing Countries: The Great Challenge forOncology in the 21st Century. One strategy, described in thechapters by Masera et al. and Cavalli, emphasizes a partnership("twinning") between institutions in developed countries andthose in underdeveloped countries, an approach that seems mostlikely to have long-term success.
Examples of the twinning approach to childhood cancer treatmenthave been in place in Central and South America, northwest Africa,and southeast Asia for as long as 10 years.3,4 These programshave reduced the rates of abandonment of treatment, relapse,and death due to toxic effects of treatment (see graph), andthe investments they have attracted have led to improvementsin access to treatment and hospital infrastructure.
Frequency of Treatment Failure during the First Year after Diagnosis and Two-Year Event-free Survival Rates among Children with Acute Lymphoblastic Leukemia Treated in a Public Hospital in Recife, Brazil.
Before the establishment of a twinning program with St. Jude Children's Research Hospital in 1994, the abandonment of treatment and the rate of relapse were major causes of failure. With the introductions of intensive, protocol-based chemotherapy and a private community support group that provides transportation, housing, and job opportunities for patients and their parents, the relapse rate has decreased markedly, and the rate of treatment abandonment has decreased from 16 percent to less than 1 percent. The use of more aggressive therapy has resulted in more deaths from infection and hemorrhage, but refinements in patient care have begun to ameliorate these complications. The most recent analysis of event-free survival shows rates similar to those in some highly developed countries. There are no data for 1990 through 1993 because the pediatric oncology unit at the Recife Hospital was closed during that period. An overlap in reporting periods occurred because the study protocol changed on April 1, 1997.
Briefly, twinning fosters interactions between public hospitalsin developing countries and established cancer treatment centers,with the goal of improving survival rates among children withcancer. The best results have been obtained when local oncologistswere recruited as program directors and asked to promote theidea of a strong pediatric oncology unit among their peers andcoordinate the training of providers. Although at first thepartner institution in the more affluent country may subsidizethe costs of treatment, these and other expenses are eventuallymet with funds raised by charitable groups in the community.Such alliances have generated sufficient momentum to allow somehospitals in Central and South America to begin sharing theirexpertise with other oncologists in the developing regions ofLatin America, by developing joint treatment protocols and consultingabout problems in the management of childhood cancer.
A Patient with Acute Lymphoblastic Leukemia at the Shanghai Children's Medical Center.
Courtesy of Dr. J.Y. Tang.
Can twinning be effective in countries that lack even rudimentaryhealth care systems? We believe that a low level of developmentdoes not pose an insurmountable obstacle to a productive partnership.In parts of Africa, for example, it may be possible to curechildren of Burkitt's lymphoma by treating them with cyclophosphamidealone, and there is evidence from Malawi that even a simplifiedtwinning program can save lives.5 Thus, a modified program concentratingon education, training, and the treatment of the most responsivecancers could be quite effective.
Most progress in pediatric cancer treatment has been stimulatedby research involving children in Western countries. Since thesusceptibility to and pathogenesis of cancer are heavily influencedby genetic background, environmental exposure, and lifestyle,we must broaden research to include cases in developing countries.It will be easier to do so if the development of pediatric-cancerunits in poor countries leads to the evolution of internationalbanks of cells and tissue and of cancer registries that collectlong-term follow-up data.
It has been said that if we are to preserve civilization, wemust make certain its benefits are available to the many, notreserved for the few. The development of curative treatmentfor children with cancer is a benchmark for medical progress,and such treatment must not be sequestered within the bordersof a few countries. The strategy we describe is only a start,but it could ignite a spirit of achievement that may ultimatelyreach even the least privileged nations.
Source Information
Dr. Ribeiro is director of the International Outreach Program and Dr. Pui is director of the Leukemia/Lymphoma Division at St. Jude Children's Research Hospital in Memphis, Tenn. Dr. Pui is also a clinical research professor at the American Cancer Society.
Cancer in Developing Countries: The Great Challenge for Oncology in the 21st Century, edited by S. Tanneberger, F. Cavalli, and F. Pannuti, was published by Zuckschwerdt, Munich, 2004.
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