(T-ALL) is associated with worse outcomes Cancer spreading into the Central nervous system (brain or spinal cord) has worse outcomes. Morphological, immunological, and genetic subtypes Person's response to initial treatment and longer length of time required (greater than 4 weeks) to reach complete remission Early relapse of ALL Minimal residual disease Genetic disorders, such as Down syndrome, and other chromosomal abnormalities (aneuploidy and translocations) Cytogenetics, the study of characteristic large changes in the chromosomes of cancer cells, is an important predictor of outcome. Some cytogenetic subtypes have a worse prognosis than others. These include: Person with t(9,22) positive-ALL (30% of adult ALL cases) and other Bcr-abl-rearranged leukemias are more likely to have a poor prognosis, but survival rates may rise with treatment consisting of chemotherapy and Bcr-abl tyrosine kinase inhibitors. A translocation between chromosomes 4 and 11 occurs in about 4% of cases and is most common in infants under 12 months. Hyperdiploidy (>50 chromosomes) and t(12;21) are good prognostic factors and also makeup 50% of pediatric ALL cases. Unclassified ALL is considered to have an intermediate prognosis risk, somewhere in-between the good and poor risk categories. Epidemiology ALL affected about 876,000 people and resulted in 111,000 deaths globally in 2015. It occurs in both children and adults with highest rates seen between the ages three and seven years. Around 75% of cases occur before the age of 6 with a secondary rise after the age of 40. It is estimated to affect 1 in 1500 children. Accounting for the broad age profiles of those affected, ALL newly occurs in about 1.7 per 100,000 people per year. ALL represents approximately 20% of adults and 80% of childhood leukemias, making it the most common childhood cancer. Although 80 to 90% of children will have a long term complete response with treatment, it remains the leading cause of cancer-related deaths among children. 85% of cases are of B-cell lineage and have an equal number of cases in both males and females. The remaining 15% of T-cell lineage have a male predominance. Globally, ALL typically occurs more often in Caucasians, Hispanics, and Latin Americans than in Africans. In the US, ALL is more common in children from Caucasian (36 cases/million) and Hispanic (41 cases/million) descent when compared to those from African (15 cases/million) descent. Pregnancy Leukemia is rarely associated with pregnancy, affecting only about 1 in 10,000 pregnant women. The management of leukemia