Acute Lymphocytic Leukemia. It is one of the first malignancies that responded to chemotherapy and one of the first to be cured in a large percentage of affected children. A slight male predominance exists in the United States, and more whites and Latin Americans are afflicted than any other ethnicity. There is a bimodal distribution, with the first peak around 3-5 years of age, the second around 50 years of age, and increasing incidence up to 2 cases per 100,000 in persons greater than 65 years old. The etiology of ALL is unknown, however, many studies have attempted to determine risk factors without any definite conclusions being reached.
Some associations continue to present themselves, such as genetic and environmental correlations.
ALL risk is significantly increased among identical twins of ALL patients. In addition, siblings of patients with ALL have a four-fold increased risk of developing the disease when compared to the general population.1 Certain congenital disorders have been associated with an increased risk of leukemia. Clusters of increased incidence exist, suggesting an infectious cause of the disease, however this is difficult to substantiate. Viruses are considered mutagens capable of inducing the clonal malignancy associated with leukemia. These symptoms are frequently misdiagnosed initially and attributed to an infectious process rather than a malignancy.