Leukemia Treatment
How is acute promyelocytic leukemia treated?
Treatment of acute promyelocitic leukemia differs from all the other subtypes of acute myelogenous leukemia because of the ability to treat the particular genetic syndrome or the genetic defect in this particular cancer. The way it's different from treating the other myelogenous leukemias is that the other leukemias need significant degrees of chemotherapy given many times over a period of one to two years to achieve remission. The acute promyelotic leukemias use chemotherapy but in addition to a drug called All-trans-Retinoic Acid, which is a retinoid, which is a Vitamin A derivative that leads to what we call the maturation of these immature cells to mature white blood cells. So that therapy, in addition to chemotherapy, leads to long term remission.
How are acute leukemias treated?
Treatment of the acute leukaemias differs from treatment of other malignancies in that we utilise similar chemotherapeutic agents of chemotherapy; standard chemotherapies, but we administer it for a long period of time. The terms that must be reviewed when treating patients or discussing treatment of patients with leukaemias, or specifically acute leukaemias, are the terms induction, consolidation and maintenance. I think it is important to mention that we initially treat patients with acute leukaemia to induce them into a remission, so that refers to the induction phase which is usually a very aggressive course of treatment that necessitates admission to the hospital for anywhere between 10 to 30 days for the initial induction phase. That's followed, if there is a remission, with several series of consolidative chemotherapy which is less aggressive but occurs more often over a period of approximately three to six months, and is followed subsequently by a maintenance phase of chemotherapy or treatment to prevent the relapse of this type of disease. So, as opposed to other malignancies where we treat, as a single type of treatment, just repeated cycles of chemotherapy that you may or may not be familiar with, leukaemias require a very ordered type of treatment where you start aggressively. You move down aggression a little bit in terms of the consolidative therapies, but provide this chemotherapy over a long period of time. Ultimately, it goes to taking as much time as necessary to destroy the abnormal stem cells that are in the bone marrow.
How are chronic myelogenous leukemias treated?
The treatment of chronic myelogenous leukaemia has changed drastically and dramatically in the past seven to ten years. The standard type of therapy for this disease used to be a combination of Interferon and other types of chemotherapy which changed completely with the introduction of a drug called Gleevec or Imatinib which was the first targeted therapy against the particular chromosomal abnormality in CML. This drug was designed and manufactured to block this particular abnormal genetic event or genetic defect. As a result of the introduction of this medication, we have now been able in most cases to either put this disease into remission or turn a disease like chronic myelogenous leukaemia into a chronic disease that doesn't lead to anything worse.
How are chronic lymphocytic leukemias treated?
The treatment of chronic lymphocytic leukaemia depends on where we are in the spectrum of disease. CLL (which is chronic lymphoid leukaemia) is in the same spectrum as small lymphocytic lymphoma or non-Hodgkin's lymphoma. We sometimes differentiate the treatment depending on where we are on that spectrum of disease. Chronic lymphoid leukaemia has a certain staging system, and we only really start any type of therapy when there is a degree of staging above three or four. However, if we're on the spectrum of disease that's closer to a non-Hodgkin's lymphoma or small lymphocytic lymphoma then we're more likely to initiate therapy when patients have difficulty related to lymph node enlargements and masses that tend to bother them. Ultimately, chronic leukaemias are not a curable disease.
Can my leukemia be treated with surgery?
Leukaemias and other haematologic malignancies are not a surgical disease. A question asked by patients when they have a diagnosis of lymphoma, which is another haematologic disease, is why can't it just be cut out? I think the best answer to that question is that when you have a disease that is so responsive to chemotherapy, then that is the treatment modality that should be used. Surgery with a scalpel, meaning a knife to cut out the reticulate disease, doesn't get at the microscopic disease that needs to be treated with chemotherapy.
What is a "bone marrow transplant" or a "stem cell transplant"?
A bone marrow transplant involves the removal or the harvesting of bone marrow from a donor, from areas where bone marrow is produced, which happen to be in the hips. What we can do now, with the technology that's been evolving over the period of, let's say, 1 to 15 to 2 years, is extract the necessary cells to achieve the same response, that is, the stem cells or the precursor cells from the peripheral blood (your blood stream). So, what used to be a bone marrow transplant is really now just the infusion of someone's stem cells, either yours or someone else's depending on the disease and depending on the treatment needed. This leads to a much more easier harvesting from a donor - it's a little easier to convince donors to become donors because it doesn't involve such significant morbidity - and the ability to provide a patient with life-saving treatment without having to go through a significant amount of pain.
Can leukemia be treated with a bone marrow transplant?
Bone marrow transplantation, or stem cell transplantation is used to treat acute leukemias as well as some chronic leukemias. The differentiation over the reason to use bone marrow transplant instead of chemotherapy to treat leukaemia is a very specialized treatment decision that's made on a case-by-case basis. But in general terms, any case of leukaemia that's not responsive to standard therapies will be treated with bone marrow transplant. Standard chemotherapy usually involves bone marrow stem cell transplant. Some cases of leukaemia that require it from the get-go get bone marrow transplant therapy up front.
What is an "allogeneic transplant"?
An allogeneic transplant is a transplant of either stem cells or bone marrow for the purpose of treating a haemologic malignancy, or some solid tumours, when it come from another individual. So, an allogeneic stem-cell transplant is a transplant that is not from you. There are syngene transplants, which means they come from an identical twin, and there are matched related transplants which means they are related to this person, match them, and can receive transplants from them. There are also matched unrelated transplants, or MUD transplants, which are matched to someone unrelated to you. Both matched unrelated transplants and matched related transplants are allogeneic, meaning they come from someone else.
What is an "autologous" transplant?
An autologous transplant is a transplant of either stem cells or bone marrow from yourself. It's almost a misnomer to talk about it as a transplant, and I like to define it as a stem cell rescue. A lot of transplants are done in order to provide you back with stem cells to repopulate your bone marrow after a chemotherapy insult. Sometimes there are certain cancers out there that require such a high degree or dose of chemotherapy that if not given your stem cells back or someone else's stem cells back you'd be without the ability to make or produce red cells, white cells, or platelets. This is why these procedures are done. To define an autologous transplant: it's one in which the stem cells that we use are from your own body after a significant degree of chemotherapy is given to you.
How can I keep my leukemia from coming back?
The whole goal of therapy for leukemia is to prevent relapse, to prevent this disease from coming back. Truly the best chance of having that happen is somewhat arbitrary or related to therapy. If a disease starts out as relatively resistant to therapy meaning, it's a secondary leukemia, one that's been as a result of prior therapy, this is a disease that may or may not be able to achieve remission and if you do achieve remission, it may be short lived unfortunately. Cases of leukemia which are de novo or primary tend to easily go into remission. The real challenge is to prevent the disease from returning. We sometimes utilize bone marrow transplants, or stem cell transplants in the effort to prevent these diseases from coming back and it depends on the amount of abnormalities, the amount of disease the patient has and their age performance status and basic outlook in terms of their disease, That determines whether or not, and some aspects of whether or not the disease will come back.