Noam Z. Drazin (Hematologist & Oncologist, Cedars-Sinai Medical Group) gives expert video advice on: What causes acute leukemia? and more...
What causes acute leukemia?
Acute leukaemias are caused by some damage, either from your own body or from some exposure, to the stem cells or to the white blood cell precursors, causing the origins of white blood cells to get damaged to some extent. The DNA material, the genetic material gets damaged. That leads to an abnormal cell that propagates itself or reproduces itself to produce a whole population of cells that are abnormal. This abnormal cell population then causes havoc by making white blood cells that don't really work well. There are different mutations that apply to different sub-types of leukaemias. The acute myelogenous leukaemias, or the AMLs, have many sub-types and there are many genetic mutations that can appear or cause this syndrome to happen. Acute lymphoid leukaemia, or ALL, which is another type of acute leukaemia, also has specific genetic mutations that can lead to this type of syndrome.
What is "acute myeloid leukemia" (AML)?
Acute myeloid leukaemia or acute myelogenous leukaemia, better referred to as AML, is one of the acute leukaemias that we treat. Better defined, the subtype of cell that's abnormal in acute myeloid leukaemia is the myeloid cell line. So, what is defined as the myeloid cell line? It is a cell line that gives rise to some of the white blood cells that help fight infection; the most common white blood cells that help fight infection. They have many subtypes of AML. There's M1 though M7; very different precursor cells, very different outcomes and very different treatments. The most important one to differentiate, between all the different subtypes, is the M3 which is the acute promyelocytic leukaemia. However, as a whole, the acute leukaemias are treated pretty much the same with cytotoxic chemotherapy with or without additional additives or additional therapies, and acute myeloid leukaemia is usually an extremely hard diagnosis to treat but cytotoxic chemotherapy can induce remissions and long terms survivals in many.
What are the different types of acute myeloid leukemia?
There are many subtypes of AML or acute myeloid leukaemia that need to be at least defined. I am not to go through specifically the different types but it can range anywhere from an M1 through an M7, and depends on the specific type of myeloid cell that is abnormal. I think the most important one to differentiate is the M3 subtype. AML M3, referred to as the acute promyelocytic leukaemia, is actually treated differently than M1 through M2 and after that, M4 through M7. The treatment is based on a molecular target that was identified after a genetic mutation was found to cause this particular type of leukaemia. The reason it is important to differentiate between M3 and all the rest is the treatment; the type of treatment, and obviously the outcome. Patients with M3 type leukaemia or acute promyelocytic leukaemia do much better; they have better outcomes and better survival than patients with the other subtypes of leukaemia.
What is "acute lymphocytic leukemia" (ALL)?
Acute lymphocytic leukemia- or sometimes referred to as acute lymphogenous leukemia- are, is a subtype or a type of leukemia. There are two subtypes of leukemias. There's acute lymphogenous leukemias and acute lymphoid leukemias.The acute lymphoid leukemias I think are the minority and happen less often than the acute myloid leukemias. The interesting thing about acute lymphoid leukemias is they are sometimes on a spectra of disease similar to lymphomas. So I think the critical aspect here, that differentiates these types of leukemias- the lymphoid leukemias versus the myloid leukemias or better said the ALL's versus the AML's- is that we're dealing with a different type of white blood cell. In the aucte lymphoid leukemias, or the ALL's, we're dealing with the lymphocytes which is a subtype of white blood cells. In the acute myloid leukemia, or the AML's, we're dealing with the myloid cells. The myloid cells produce white blood cells that help fight infection. The lymphoid cells do that in a different way. So it's a different population of cells that are being affected by a mutation.
What is "acute promyelocytic leukemia" (APL)?
Acute promyelocytic leukaemia, or APL, or sometimes referred to as M3 subtype of AML, is the most interesting of the AMLs or the acute myeloid leukaemias in that we have identified the actual genetic mutation that leads to the development of this cancer. Why is that important? Well, it's important because the particular mutation that's found, specifically what's called the PMLRAR alpha mutation, is susceptible to a plain vitamin, and a vitamin therapy given to these patients can convert these white blood cells, very immature white blood cells, to normal white blood cells. So, in a disease in which we give chemotherapy, which can be very damaging and dangerous to patients with acute myeloid leukaemia, patients with the M3 subtype are able to not only achieve remissions and cures with chemotherapy, but with a combination of a targeted therapy against a particular mutation, we can achieve very long term remissions.