Acute Lymphoblastic Leukemia Essay -- Disease, Disorders

Acute lymphoblastic leukaemia is the most common childhood cancer accounting for around 20-30% of all childhood neoplasms. Annual incidence rates vary worldwide between one and four cases per 100,000, primarily in children ages two - six years old (1). The disease is less common in adults, with only around 1,000 cases being diagnosed annually and with a significantly lower cure rate, rarely exceeding 40%. In turn, infants diagnosed under the age of one have an even poorer survival rate of 30%. Several studies in monozygotic twins and neonatal blood smears have indicated a clear prenatal origin for childhood cases, detecting specific genetic abnormalities in prenatal samples, which may act as initiating events although clearly further postnatal events are required for transformation (2; 3; 4). TEL-AML fusion genes, for example, were found in 1% of newborn samples, which is significantly greater than the number of ALL cases, clearly demonstrating that there may often be a prenatal ori gin for initial genetic aberrations and that further genetic alterations are necessary to develop ALL (3; 4). A small study further supports a prenatal origin in a pair of monozygotic twins with childhood B cell precursor (BCP) ALL with identical cytogenetic abnormalities, signifying a prenatal foundation, as well various contrasting genetic lesions illustrating that further genetic events are required to generate a malignant phenotype (2). A few inherited syndromes such as Down’s syndrome, Bloom’s syndrome and other genetic syndromes have also been associated with a risk. Environmental factors may also play a role in the development of ALL such as exposure to radiation, chemotherapy and possibly infections. Two infection based theories based on observ... ...entical twins. Maia, AT, et al. 2202-2206, s.l. : Nature Leukemia, 2003, Vol. 17. 3. Chromosome translocations and covert leukemic clones are generated during normal fetal development. Mori, Hiroshi, Colman, Susan and al, et. 12, s.l. : PNAS, 2002, Vol. 99. 8242-8247. 4. Acute Lymphoblastic Leukaemia. Pui, Ching-Hon, Robison, Leslie and Look, A Thomas. 1030-43, s.l. : Lancet, 2008, Vol. 371. 5. Infections and immune factors in cancer: the role of epidemiology. Kinlen, Leo. 6341-6348, s.l. : Nature Oncogene, 2004, Vol. 23. 6. Kanwar, Vikramjit S. Pediatric Acute Lymphoblastic Leukemia. Medscape Reference. [Online] November 21, 2011. http://emedicine.medscape.com/article/990113-overview. 7. Targeting paediatric acute lymphoblastic leukaemia: novel therapies currently in development. Lee-Sherick, Alisa B, et al. 2010, British Journal of Haematology, pp. 295-311.