All adults with Acute Myelogenous Leukemia (AML) in Vancouver are initially treated with a combination of two drugs: cytosine arabinoside (Ara-C) and daunorubicin. This combination is widely accepted as the best initial therapy for AML.
With this treatment, 50-70% of all AML patients will have no detectable leukemia blast cells in their bone marrow after 1-2 courses of chemotherapy. This is referred to as a complete remission.
ATRA, a derivative of Vitamin A, is a highly effective treatment for the M3 variant of AML, also known as acute promyelocytic leukemia or APL. It is used in combination with Ara-C and daunorubicin because it reduces the complication rate seen with chemotherapy; particularly the bleeding tendency that is a hallmark of M3 AML and it improves the complete remission rate to greater than 90%. ATRA is NOT a useful drug for other forms of AML.
Arsenic Trioxide for M3 AML
Arsenic compounds have recently been shown to be effective in M3 AML. In Vancouver patients may receive this drug if they have a recurrence of M3 AML after standard treatment.
Once patients with AML have achieved their first complete remission, subsequent therapy is individualised.
In general, eligible patients with a matched sibling will be offered a blood and marrow transplant as soon as they achieve a first remission. Patients with favourable chromosomal abnormalities, patients with other significant health problems, or patients with M3 AML are exceptions to this general recommendation
It is possible for older patients to undergo a modified blood and marrow transplant (reduced intensity conditioning or RIC transplant), but this is not a standard practice at present
Younger, healthier patients in first complete remission, without a matched sibling, with bad chromosomal abnormalities, a very high white blood cell count at diagnosis, or a poor initial response to therapy may be considered for an unrelated donor bone marrow transplant.
Patients not receiving some type of bone marrow transplant in first remission usually receive two or three further cycles of consolidation chemotherapy, a total of three cycles, over a 3 to 4-month period.
A blood and marrow transplant may be considered for some patients who are 65 years or younger if AML recurs after consolidation chemotherapy.
For all AML patients who are 60 years old or younger, three cycles of chemotherapy are expected to cure 40% of patients. Research suggests that those patients with good chromosomal changes or M3 AML will have a higher cure rate, of at least 50%, with this approach.
For patients older than 60 years of age, except for those with M3 AML, results are not as good, 10-20% of patients continue for 2 years without a recurrence of AML.
Blood and Marrow Transplant
AML patients in Vancouver who have undergone a matched sibling bone marrow transplant in first complete remission have had a cure rate in excess of 60%. When an unrelated donor is used or when the bone marrow transplant is done for recurrent AML, the cure rate is about 30%.
The outcome with autologous bone marrow transplant has been more difficult to determine due to the small number of patients (with various types of AML) who have had this procedure. Nevertheless, it is not anticipated that autologous bone marrow transplant will be superior to consolidation chemotherapy in most circumstances, but may have a role in selected patients with AML who relapse after three cycles of chemotherapy.