ABSTRACT
Overall survival is about 85% for ALL and 60% for AML . The 5-year overall survival for high-risk or relapsed patients who are treated with an allogeneic bone marrow transplant with or without total body irradiation is approximately 50% . Leukemia is a hematological, or “liquid” malignancy of white blood cells (WBCs) from the bone marrow, rather than a solid tumor . The predominant blast cell in the bone marrow of ALL patients is the lymphocyte, one of the five types of WBCs . ALL is subcategorized as being comprised of malignant B-lymphocytes (85% of ALL cases) or malignant T-lymphocytes . Prognosis is generally better for those with B-cell ALL . The best prognosis category (with 80% 4-year event-free survival) is “standardrisk ALL,” comprised of the two-thirds of B-cell ALL patients who present with a WBC count below 50,000/mL at age 1 to 10 years . The other one-third of B-cell ALL patients, classified as having high-risk ALL, have a 4-year
event-free survival rate of 65% . The initial response to chemotherapy is also prognostic . Patients with a “rapid early response” (remission achieved after 1 to 2 weeks of the start of chemotherapy) have a better prognosis than those with a “slow early response” (remission not achieved until 1 month of chemotherapy has been given) . Complete remission is obtained after 1 month of chemotherapy in over 95% of ALL and approximately 85% of AML patients . Patients younger than 20 years old generally do better than older patients (van Kempen-Harteveld et al . 2008) .
