Cancer knows no boundaries and as such affects children throughout the world. It is estimated that between 160,000 and 250,000 children world-wide are diagnosed with cancer each year, and approximately 90,000 will eventually die from their illness.
In developed countries like the United States , Canada , Western European countries, Japan and Australia , cancer remains the most common disease killer of children. In developing countries, more than one in two children diagnosed with cancer are likely to die.2 This is because cancer is detected late and only a small proportion of children have access to the comprehensive cancer treatments currently available in the developed world. Childhood cancer is becoming a more important health issue for these countries and the world community as infectious diseases and diarrhea become increasingly eliminated.
In the U.S. and other developed countries, the 1970s-80s brought the advent of chemotherapy ‘cocktails’ applied to childhood cancer, where toxic compounds that preferentially killed the tumor cells kept many children from death. In spite of tens of millions of public dollars being allocated towards clinical trial research in the U.S. in the past decade, there has been no change in survivorship of childhood cancer in the past 10 years.2 From 1975 to 1998 the annual death rate from childhood cancer in the U.S. declined at a rate of 2.7% per year. Despite very aggressive therapies that approach the limits of tolerability for the child, the overall survival rate for childhood cancer has remained unchanged since 1998. One in four children who are diagnosed with cancer in the U.S. will die within five years of their diagnosis, and 30% of those that do survive have severe side effects, including cognitive deficits, kidney failure, heart failure, and secondary cancers caused from the traditional toxic treatments. Because of the high level of toxicity associated with many current treatments and the plateau in survivorship rates, future success is dependent upon the development of new therapeutic approaches.
Newly emerging cancer therapy is focused on drugs that kill only the cancer making them less toxic to the normal cells of the patient. This type of treatment is accomplished by using molecular genetic approaches to identify the ‘Achilles heel’ of each specific tumor type, then attacking this weak spot in a highly specific manner. This “targeted therapeutics” or “precision medicine” has had great success in a number of adult cancers. Pediatric cancers are often different from adult cancers on the molecular level. Children’s cancers often have different types of mutations and genetic pathways leading to their specific tumors. As such, stargeted therapies must be developed specifically for pediatric cancer. It is imperative that research initiatives take place for childhood cancer that utilizes and integrates the latest molecular techniques for pediatric cancers, including: whole genome sequencing, comparative genomic hybridization, large-scale re-sequencing of key oncogenes, proteomic profiling (particularly signaling pathways; phosphoproteomic profiling), and mRNA profiling.
The identification of such therapeutic targets is essential to the future progress in identifying more effective therapies for children with cancer. Specifically, “target identification” is the first step in the high throughput drug screening pipeline (HTS), enabling subsequent assay development, high throughput screening, drug development, and pre-clinical and clinical studies. Through the development of molecularly targeted drugs for children with cancer, children world-wide could benefit from additional cancer therapies. Children would benefit from additional drugs leading to a greater number of cures.
1 International Agency for Research on Cancer, Globocan, 2002
2 Global Action Against Cancer ( Geneva : UICC/WHO, updated edition 2005)
3 Ries, L. A. G., Eisner, M. P., Kosary, C. L., Hankey, B. F., Miller, B. A., Clegg, L., Mariotto, A., Feuer, E. J., and Edwards, B. K. SEER Cancer Statistics Review, 1975-2002. 2005. National Cancer Institute. Bethesda , MD.