Untreated Adult Acute Lymphoblastic Leukemia

Standard treatment options for remission induction therapy:

Most current induction regimens for adult acute lymphoblastic leukemia (ALL) include prednisone, vincristine, and an anthracycline. Some regimens also add other drugs, such as asparaginase or cyclophosphamide. Current multiagent induction regimens result in complete response rates that range from 60% to 90%.

Two subtypes of adult ALL require special consideration. B-cell ALL which expresses surface immunoglobulin and cytogenetic abnormalities such as t(8;14), t(2;8), and t(8;22)] is not usually cured with typical ALL regimens. Aggressive brief duration high-intensity regimens similar to those used in aggressive non-Hodgkin's lymphoma have shown high response rates and cure rates (75% complete remission; 40% failure-free survival). T-cell ALL, including lymphoblastic lymphoma, similarly has shown high cure rates when treated with cyclophosphamide-containing regimens. Whenever possible, such patients should be entered in clinical trials designed to improve the outcomes in these subsets. (Refer to the PDQ summary on Adult Non-Hodgkin's Lymphoma Treatment for more information on B-cell (Burkitt's) lymphoma and T-cell (lymphoblastic) lymphoma.)

Since myelosuppression is an anticipated consequence of both the leukemia and its treatment with chemotherapy, patients must be closely monitored during remission induction treatment. Facilities must be available for hematological support as well as for the treatment of infectious complications.

Supportive care during remission induction treatment should routinely include red blood cell and platelet transfusions when appropriate. Randomized trials have shown similar outcomes for patients who received prophylactic platelet transfusions at a level of 10,000 per cubic millimeter rather than 20,000 per cubic millimeter. The incidence of platelet alloimmunization was similar among groups randomly assigned to receive pooled platelet concentrates from random donors; filtered, pooled platelet concentrates from random donors; ultraviolet B-irradiated, pooled platelet concentrates from random donors; or filtered platelets obtained by apheresis from single random donors. Empiric broad spectrum antimicrobial therapy is an absolute necessity for febrile patients who are profoundly neutropenic. Careful instruction in personal hygiene, dental care, and recognition of early signs of infection are appropriate in all patients. Elaborate isolation facilities, including filtered air, sterile food, and gut flora sterilization are not routinely indicated but may benefit transplant patients. Rapid marrow ablation with consequent earlier marrow regeneration decreases morbidity and mortality. White blood cell transfusions can be beneficial in selected patients with aplastic marrow and serious infections that are not responding to antibiotics. Prophylactic oral antibiotics may be appropriate in patients with expected prolonged, profound granulocytopenia (<100 per cubic millimeter for 2 weeks), although further studies are necessary. To detect the presence or acquisition of resistant organisms, serial surveillance cultures may be helpful in such patients. The use of myeloid growth factors during remission induction therapy appears to decrease the time to hematopoietic reconstitution.

Treatment options for remission induction therapy under clinical evaluation:

Clinical trials are ongoing, and patients should be considered for these studies.

Standard treatment options for central nervous system (CNS) prophylaxis:

The early institution of CNS prophylaxis is critical to achieve control of sanctuary disease.

1. Cranial irradiation plus intrathecal (IT) methotrexate.

2. High-dose systemic methotrexate and IT methotrexate without cranial irradiation.

3. IT chemotherapy alone.