Children are not equally susceptible to cancer. Some are at high risk, as recognized clinically and epidemiologically. Laboratory studies of these children and their neoplasms have recently provided new understanding of human carcinogenesis, which would not have come from animal experimentation alone. Certain mechanisms are proving to be the same for a spectrum of cancers. Hence, from the study of rarities, generalizations are becoming apparent, and they have implications for medical practice.
Clinicians have played an important role in this regard, because their observations have led to the recognition of high-risk groups. Sometimes a single case report starts an avalanche of productive research, as when Bruton1 first described congenital X-linked a-γ-globulinemia in 1952.
When mechanisms are delineated, strategies can be developed for prevention, early diagnosis, and better treatment. The pediatrician in practice should know the characteristics that put children at high risk of cancer, so the parents can be advised of exposures to be avoided. This will enable the physician to adjust the frequency and nature of examinations to allow detection of neoplasia early when the prospect for cure is greatest.
LEUKEMIA
Disorders With Preesistent Chromosomal Aberrations
Down Syndrome. In 1953 to 1955, individuals with Down syndrome were first noted to have a high frequency of leukemia. The observation was simple: three or four cases were identified within a short time on pediatric wards in Paris, North Carolina, and Minnesota.
Utility of fetal facial markers on a second trimester genetic sonogram in screening for Down syndrome in a high-risk Thai population
