With regard to adult acute lymphocytic leukemia (ALL) treatment studies in various centers have shown that the best result in terms of remission is achieved when induction chemotherapy is initiated with the following combination: Corticosteroids (prednisone or dexamethasone), vincristine, daunorubicin as well as L-asparaginase.
After remission is induced with this combination chemotherapy, maintenance therapy to maintain remission needs to be followed through with 6-mercaptopurine as well as methotrexate.
During all of these therapies supportive measures are given to ensure that the function of liver and kidney is monitored and that infections are prevented. If they occur, they are dealt with appropriately. The initial remission response rate is 60 to 85% (younger patients fare better than older ones). The remission, however, lasts only for 23 (+/- 4) months and the 5 year survival rate is about 40%. One of the limiting factors are the side effects of chemotherapy and the fact that chemotherapy medication is not only wiping out the leukemia cells, but is also attacking stem cells that produce immune cells in the bone marrow and affects the rapidly dividing cells of the colonic mucosa as well. The end result is that the colon wall will leak E.coli bacteria into the blood stream that can now cause septicemia, which the immune system is too weak to handle. The risk of dying within 24 hours of untreated sepsis from E.coli is about 25%.
About 5 to 10% of adult ALL patients will present with disease of the central nervous system. However, the clinician must be very astute as in the beginning, when the chances of therapeutic intervention are greatest, the symptoms are very subtle. The treatment regimen for that is very similar as that described above for childhood ALL. Without prophylaxis approximately 40% of patients with ALL would develop CNS leukemia. There are certain predictors in the blood tests (for instance high LDH, high white blood cell count and others), which are associated with a high probability for leukemia in the central nervous system.
Bone marrow transplantation for adult acute lymphocytic leukemia
Most hematologists are recommending at present that high risk ALL patients get a bone marrow transplant with the first remission, as they seem to fare better than with chemotherapy alone. With the normal risk ALL patient (risk based on the lab data) a bone marrow transplant would only be recommended with the second remission, if necessary. Each case is different and the availability of a transplant donor, how well the immune tests fit, and personal factors enter into the equation.
Prognosis for adult acute lymphocytic leukemia
The best therapy protocol at this point yields a 5-year survival rate of 40%. However, below 50 years of age the leukemia survival rate is 20% better than above 50 years of age.
The survival rates fluctuate according to the population tested and according to the mixture of chemotherapeutic agents used (Ref. 1 and 2).
