Patients, Caregivers & Families
What are stem cells? What is bone marrow?
Stem cells are most immature, most primitive blood cells. Stem cells can divide and develop into any blood cells, such as red blood cells, white blood cells, and platelets. Stem cells usually live only in bone marrow, not flowing into peripheral blood. So all the blood cells are produced in bone marrow. The biggest amount of bone marrow is in the largest bone in the body, the hip bone.
What is stem cell transplant? What is autologous and allogeneic stem cell transplant?
Transplant is the process to replace your bone marrow, otherwise known as the body’s blood production system. There are 2 types of transplants. One is autologous stem cell transplant, the other is allogeneic stem cell transplant. If your blood system is replaced by your own blood system, it is called autologous stem cell transplant. If your blood system is replaced by someone else’s blood system, it is called allogeneic stem cell transplant.
What is autologous stem cell transplant used for? What is the process?
The purpose of autologous stem cell transplant is to give very high dose chemotherapy to patients. For patients whose tumor (mainly myeloma, lymphoma, or leukemia) responds to chemotherapy but are not cured, the chemotherapy may be much more effective if a higher dose of chemotherapy can be given, and may even be a cure for some lymphomas or leukemias. But too many normal blood cells may be killed also, and the patient may suffer from very low blood counts for a long time. To avoid this problem, we collect patient’s own stem cells beforehand (called stem cell collection or stem cell harvest), freeze and store them. Then, when we start the process of autologous stem cell transplant, we give very high dose chemotherapy to the patient first (this may take about one week for lymphoma patients, one day for most myeloma patients), then we thaw the patient’s own stem cells and give them back to the patient. Stem cell transplant/infusion is done as an IV infusion through a catheter. With autologous stem cell transplant, blood counts will recover most reliably in 2 weeks. Thus, we can give a very high dose of chemotherapy but the period of low blood counts is only about 2 weeks.
Autologous stem cell transplant is shown to improve the disease control and survival in myeloma, lymphoma, and leukemia. Occasionally, it is being used for autoimmune diseases for immunosuppression purposes.
What is allogeneic stem cell transplant used for? What is the process?
The process itself is similar to autologous stem cell transplant. First the patient needs to receive chemotherapy and/or radiation therapy, called “conditioning”. The purpose of conditioning is to destroy the patient’s own bone marrow, both good and bad cells, and also give enough immunosuppression to the patient so that the patient’s body can “accept” the stem cells by the donor. After the conditioning, the patient will receive a stem cell infusion from a donor previously identified. This will take place in the patient’s hospital room by IV infusion. After transplant, it will take about 2 weeks for the cell counts to come back (called “engraftment”).
Allogeneic stem cell transplant is the process to replace the patient’s diseased bone marrow with donor’s healthy bone marrow (or stem cells). So, this process is mainly used for acute and chronic leukemia, myelodysplastic syndrome (MDS), and myelofibrosis and myeloprolifereative disorders (MPD). Also allogeneic stem cell transplant may be used for severe aplastic anemia and bone marrow failure syndrome. In addition, allogeneic stem cell transplant can be used for lymphoma or myeloma patients who relapsed after autologous stem cell transplant, or who have very high risk diseases.
What is leukemia?
Leukemia is cancer of blood cells. Depending on what blood cells become neoplastic (cancerous), leukemias can be divided into myeloid and lymphoid. Also, it is called acute or chronic depending on how fast it progresses.
Acute Myelogenous Leukemia (AML): Almost all patients require chemotherapy. Most of the patients go into remission with chemotherapy but many patients relapse, and almost all relapsed patients need allogeneic stem cell transplant. Allogeneic stem cell transplant is curative in about half of the cases.
Chronic Myelogenous Leukemia (CML): Majority of patients are treated with so-called tyrosine kinase inhibitors (TKI, such as Imatinib (Gleevec), Nilotinib (Tasigna) or Dasatibnib (Sprycel) and go into long-term remission, thus may not need transplant. However, a small fraction of patients are refractory to TKIs and need transplant. A small number of patients also transform to accelerated phase (AP) or blastic crisis (BC), a more aggressive form of the disease, just like acute leukemia. Once the transformation happens, moving into transplant is strongly recommended once the patient in placed back into the chronic phase. Allogeneic stem cell transplant is curative for the majority of cases in chronic phase.
Acute Lymphoblastic Leukemia (ALL): More common for children but also common for older adults. ALL in children is mostly curable with chemotherapy only, but adult ALL is a difficult disease and most likely will need an allogeneic stem cell transplant to cure the disease.
Chronic Lymphocytic Leukemia (CLL): A very common, chronic leukemia. Many early phase patients even do not need any treatment at all for a long time. Advanced phase patients need treatment, and refractory patients may need allogeneic stem cell transplant.
What is lymphoma?
Lymphoma is cancer of lymphocytes and is divided into Hodgkin’s lymphoma and non-Hodgkin lymphoma (NHL). Many patients have lymphadenopathy, or swollen lymph nodes, and may have other symptoms such as fever, night sweats and weight loss. Among NHL, there are indolent lymphomas such as follicular lymphoma, aggressive lymphomas such as diffuse large cell lymphoma or mantle cell lymphoma, and very aggressive lymphomas such as lymphoblastic lymphoma and Burkitt’s lymphoma.
Hodgkin’s lymphoma is highly curable with chemotherapy only, but relapsed and/or refractory cases many need autologous or sometimes allogeneic stem cell transplant. NHL is responsive to chemotherapy, and many patients are cured with chemotherapy only but about half of the patients may need mainly autologous stem cell transplant if the disease relapses. Patients who relapse after autologous stem cell transplant may need allogeneic stem cell transplant.
What is multiple myeloma?
Multiple myeloma is cancer of plasma cells. Plasma cells are mature lymphocytes, specializing in producing antibodies. Antibodies will protect human body by attacking all bacteria, viruses etc. coming from outside. One plasma cell produces only one type of antibody. Usually there are hundreds of thousands of different antibodies in human body, produced by hundreds of thousands of plasma cells. When one of these plasma cells become cancerous, they produce only one type of (defective) antibody in a huge amount, and this abnormal antibody is detected as M-protein, which reflects the amount of disease the person has. Because plasma cells usually live in bone marrow, myeloma tends to stay in bone marrow. When myeloma replaces normal bone marrow, it may cause bone pain and/or fractures. If myeloma replaces bone marrow, it may cause anemia and/or low platelet counts because normal blood production in the marrow is hampered. Myeloma can also causes high calcium and/or kidney failure.
Myeloma is usually treated with induction treatment with agents such as lenalidomide, bortezomib and steroids. Next, most patients will undergo autologous stem cell transplant to improve the outcome further. Patients who relapse after autologous stem cell transplant may need allogeneic stem cell transplant.
What is graft-versus-host disease (GVHD)? What is graft-versus-leukemia (GVL) effect?
GVHD can only be caused by allogeneic transplants, and is caused by donor stem cells attacking the recipient body. It may happen about 40% (Sibling donor) to 50% (unrelated donor) of all patients. It may present as skin disease (rash), gut disease (diarrhea or nausea) or liver disease (liver enzyme elevations and jaundice). Most of GVHD are mild to moderate, and may not need any treatment or can be controlled with immunosuppressive agents such as steroids. However, in about 10% of patients GVHD may become out of control and may be fatal. We are always trying to develop better ways of preventing and treating GVHD, and we are making great progress.
If you have mild GVHD, GVHD itself can be easily controlled, and at the same time, donor cells will attack leukemia/lymphoma or tumor cells. This is called graft-versus-leukemia/lymphoma (GVL) or graft-versus-tumor (GVT) effect, and that is the reason allogeneic stem cell transplants can cure the disease when chemotherapy cannot.
External Patient Resource(s):
A Brave Heart Foundation
Acts as an additional layer of love and support in every cancer Unit: to encourage every patient to have A Brave Heart. Emotional and mental strength and stability play such a vital role in the overall fight and tolerance for the journey of cancer care. Its goal is to help improve patient state of mind during the treatment process. It consists of a team of supporters, volunteers, and licensed massage therapists to lift the spirits of those newly diagnosed with cancer: focusing on providing care packages to the in-patient group, and therapeutic massages to the out-patient group.
More information can be found at: www.abraveheart.com