Acute Leukemias - Republican Scientific Medical Library

Acute Lymphoblastic Leukemia:
Epidemiology and Etiology
Daniel Wartenberg, Frank D. Groves, Aaron S. Adelman
Contents
5.1 Introduction .................... 77
5.2 Demographic Patterns ............ 78
5.2.1 Incidence ................... 78
5.2.2 Survival .................... 78
5.2.3 Mortality ................... 80
5.2.4 Sex Differences ............... 80
5.2.5 Race Differences .............. 80
5.2.6 Age Differences .............. 80
5.2.7 Parental and Birth Characteristics . . 80
5.2.8 Socioeconomic Status .......... 82
5.3 Etiology ....................... 82
5.3.1 Biological Factors ............. 82
5.3.1.1 Genetics of Childhood ALL . 82
5.3.1.2 Cytogenetic Abnormalities . . 83
5.3.1.3 Infectious Etiology ....... 83
5.3.1.4 Postnatal Infection by
a Specific Leukemogenic
Pathogen .............. 83
5.3.1.5 Prenatal Infection by
a Specific Leukemogenic
Pathogen .............. 84
5.3.1.6 Delayed Exposure
to Pathogens in General . . . 84
5.3.2 Physical Factors .............. 85
5.3.2.1 Ionizing Radiation ........ 85
5.3.2.2 Nonionizing Radiation ..... 85
5.3.3 Chemical Factors ............. 86
5.3.3.1 Solvents ............... 86
5.3.3.2 Pesticides .............. 87
5.3.3.3 Outdoor Air Pollution ..... 87
5.3.3.4 Tobacco Smoke ......... 88
5.3.3.5 Diet ................. 88
5.3.3.6 Maternal Pharmaceutical Use 88
5.4 Summary ...................... 89
References ......................... 89
5.1 Introduction
Acute lymphoblastic leukemia (ALL), also known as
acute lymphocytic leukemia, is a malignant neoplasm
of the lymphocyte precursor cells, or lymphoblasts, that
occurs annually in nearly 4000 people in the US [51].
Leukemic lymphoblasts have exaggerated and uncontrolled
growth, fail to mount a normal immune response,
and cause a drop in production of normal bone
marrow cells that leads to a deficiency of circulating red
cells (anemia), platelets (thrombocytopenia), and white
cells other than lymphocytes (especially neutrophils, or
neutropenia) [146]. Both T-cell and B-cell precursors
can give rise to ALL; B-cell ALL represents about 88%
of all cases.
ALL afflicts whites more than blacks, males more
than females, and those in Western, affluent countries
more than those in the developing world. It often occurs
in clusters, or small geographic aggregations of cases,
has been studied extensively, and yet we still know surprisingly
little about what causes it. It appears that chromosomal
alterations and mutations that are associated
with the disease may be inherited from pregnancy or
develop through infancy and childhood, and these alterations
and mutations then interact with certain environmental
exposures which can lead to at least some
types of ALL.