What are leukemia treatment options?
There are a number of different medical approaches to the treatment of leukemia. Treatment will typically depend upon the type of leukemia, the patient's age and health status, as well as whether or not the leukemia cells have spread to the cerebrospinal fluid. The genetic changes or specific characteristics of the leukemia cells as determined in the laboratory can also determine the type of treatment that may be most appropriate.
Watchful waiting may be an option for some people with a chronic leukemia who do not have symptoms. This involves close monitoring of the disease so that treatment can begin when symptoms develop. Watchful waiting allows the patient to avoid or postpone the side effects of treatment. The risk of waiting is that it may eliminate the possibility of controlling the leukemia before it worsens.
Treatments for leukemia include chemotherapy (major treatment modality for leukemia), radiation therapy, biological therapy, targeted therapy, and stem cell transplant. Combinations of these treatments may be used. Surgical removal of the spleen can be a part of treatment if the spleen is enlarged.
Acute leukemia needs to be treated when it is diagnosed, with the goal of inducing a remission (absence of leukemia cells in the body). After remission is achieved, therapy may be given to prevent a relapse of the leukemia. This is called consolidation or maintenance therapy. Acute leukemias can often be cured with treatment.
Chronic leukemias are unlikely to be cured with treatment, but treatments are often able to control the cancer and manage symptoms. Some people with chronic leukemia may be candidates for stem cell transplantation, which does offer a chance for cure.
Many patients opt to receive a second opinion before beginning treatment for leukemia. In most cases, there is time to receive a second opinion and consider treatment options without making the treatment less effective. However, in rare cases of very aggressive leukemias, treatment must begin immediately. One should discuss with a doctor the possibility of obtaining a second opinion and any potential delays in treatment. Most doctors welcome the possibility of a second opinion and should not be offended by a patient's wish to obtain one.
Chemotherapy is the administration of drugs that kill rapidly dividing cells such as leukemia or other cancer cells. Chemotherapy may be taken orally in pill or tablet form, or it may be delivered via a catheter or intravenous line directly into the bloodstream. Combination chemotherapy is usually given, which involves a combination of more than one drug. The drugs are given in cycles with rest periods in between.
Sometimes, chemotherapy drugs for leukemia are delivered directly to the cerebrospinal fluid (known as intrathecal chemotherapy). Intrathecal chemotherapy is given in addition to other types of chemotherapy and can be used to treat leukemia in the brain or spinal cord or, in some cases, to prevent spread of leukemia to the brain and spinal cord. An Ommaya reservoir is a special catheter placed under the scalp for the delivery of chemotherapy medications. This is used for children and some adult patients as a way to avoid injections into the cerebrospinal fluid.
Side effects of chemotherapy depend on the particular drugs taken and the dosage or regimen. Some side effects from chemotherapy drugs include hair loss, nausea, vomiting, mouth sores, loss of appetite, tiredness, easy bruising or bleeding, and an increased chance of infection due to the destruction of white blood cells. There are medications available to help manage the side effects of chemotherapy.
Some adult men and women who receive chemotherapy sustain damage to the ovaries or testes, resulting in infertility. Most children who receive chemotherapy for leukemia will have normal fertility as adults, but depending on the drugs and dosages used, some may have infertility as adults.
Biological therapy is any treatment that uses living organisms, substances that come from living organisms, or synthetic versions of these substances to treat cancer. These treatments help the immune system recognize abnormal cells and then attack them. Biological therapies for various types of cancer can include antibodies, tumor vaccines, or cytokines (substances that are produced within the body to control the immune system). Monoclonal antibodies are antibodies that react against a specific target that are used in the treatment of many kinds of cancer. An example of a monoclonal antibody used in the treatment of leukemia is alemtuzumab, which targets the CD52 antigen, a protein found on B-cell chronic lymphocytic leukemia (CLL) cells. Interferons are cell signaling chemicals that have been used in the treatment of leukemia.
Side effects of biological therapies tend to be less severe than those of chemotherapy and can include rash or swelling at the injection site for IV infusions of the therapeutic agents. Other side effects can include headache, muscle aches, fever, or tiredness.
Targeted therapies are drugs that interfere with one specific property or function of a cancer cell, rather than acting to kill all rapidly growing cells indiscriminately. This means there is less damage to normal cells with targeted therapy than with chemotherapy. Targeted therapies may cause the target cell to cease growing rather than to die, and they interfere with specific molecules that promote growth or spread of cancers. Targeted cancer therapies are also referred to as molecularly targeted drugs, molecularly targeted therapies, or precision medicines.
Monoclonal antibodies (described above in the section on biologic therapy) are also considered to be targeted therapies since they specifically interfere and interact with a specific target protein on the surface of cancer cells. Imatinib (Gleevec) and dasatinib (Sprycel) are examples of targeted therapies that are used to treat CML, some cases of ALL, and some other cancers. These drugs target the cancer-promoting protein that is formed by the BCR-ABL gene translocation.
Targeted therapies are given in pill form or by injection. Side effects can include swelling, bloating, and sudden weight gain. Other side effects can include nausea, vomiting, diarrhea, muscle cramps, or rash.
Radiation therapy uses high energy radiation to target cancer cells. Radiation therapy may be used in the treatment of leukemia that has spread to the brain, or it may be used to target the spleen or other areas where leukemia cells have accumulated.
Radiation therapy also causes side effects, but they are not likely to be permanent. Side effects depend on the location of the body that is irradiated. For example, radiation to the abdomen can cause nausea, vomiting, and diarrhea. With any radiation therapy, the skin in the area being treated may become red, dry, and tender. Generalized tiredness is also common while undergoing radiation therapy.
Stem cell transplant
In stem cell transplantation, high doses of chemotherapy and/or radiation are given to destroy leukemia cells along with normal bone marrow. Then, transplant stem cells are delivered by an intravenous infusion. The stem cells travel to the bone marrow and begin producing new blood cells. Stem cells may come from the patient or from a donor.
Autologous stem cell transplantation refers to the situation in which the patient's own stem cells are removed and treated to destroy leukemia cells. They are then returned to the body after the bone marrow and leukemia cells have been destroyed.
An allogeneic stem cells transplant refers to stem cells transplanted from a donor. These may be from a relative or an unrelated donor. A syngeneic stem cell transplant uses stem cells taken from a healthy identical twin of the patient.
Stem cells may be removed (harvested) in different ways. Typically, they are taken from the blood. They can also be harvested from the bone marrow or from umbilical cord blood.
Stem cell transplantation is done in a hospital, and it is necessary to remain in the hospital for several weeks. Risks of the procedure include infections and bleeding due to the depletion of normal blood cells. A risk of stem cell transplant with donor cells is known as graft-versus-host disease (GVHD). In GVHD, the donor white blood cells react against the patient's normal tissues. GVHD can be mild or very severe, and often affects the liver, skin, or digestive tract. GVHD can occur at any time after the transplant, even years later. Steroids or medications that suppress the immune response may be used to treat this complication.
Chimeric antigen receptor (CAR) T-cell treatment
Chimeric antigen receptor (CAR) T-cell treatment is a new form of treatment in which a patient's own normal T lymphocytes are re-engineered in a laboratory to attack the leukemia cells and are then reintroduced into the patient's bloodstream. This treatment has been used for people with B-cell lymphomas that have relapsed or are refractory to treatment. It is also an approved treatment option for certain cases of leukemia. The U.S. FDA approved tisagenlecleucel (Kymriah) in 2018 for the treatment of patients up to 25 years of age with B-cell precursor acute lymphoblastic leukemia (ALL) that is refractory or in second or later relapse.
CAR-T therapy is also available in clinical trials. Cytokine-release syndrome (CRS) is a potentially serious side effect frequently associated with CAR T-cell therapy. Cytokines are chemical messengers produced when the CAR T-cells multiply in the body and kill cancer cells. CRS may cause a range of symptoms from mild flu-like symptoms to more serious symptoms including fast heart rate, low blood pressure, and heart problems. Other side effects can include nerve damage, suppressed immune function, and a condition known as tumor lysis syndrome that results when cancer cells are rapidly destroyed.
Because CAR T-cell therapy is so new, the patients who have had this treatment have not been followed over the long term. Studies are under way to determine whether CAR-T treatment may be useful in other types of leukemia.
Because many of the treatments for leukemia deplete normal blood cells, increasing the risk for bleeding and infection, supportive treatments may be needed to help prevent these complications of treatment. Supportive treatments may also be needed to help minimize and manage unpleasant side effects of medical or radiation therapy.
Types of supportive and preventive treatments that can be used for patients undergoing treatment for leukemia include the following:
- Vaccines against the flu or pneumonia
- Blood or platelet transfusions
- Anti-nausea medications
- Antibiotics or antiviral medications to treat or prevent infections
- White blood cell growth factors to stimulate white blood cell production (such as granulocyte-colony stimulating factor [G-CSF], made up of filgrastim [Neupogen] and pegfilgrastim [Neulasta] and granulocyte macrophage-colony stimulating growth factor [GM-CSF], made up of sargramostim [Leukine])
- Red cell growth factors to stimulate red blood cell production (darbepoetin alfa [Aranesp] or epoetin alfa [Procrit])
- Intravenous injections of immunoglobulins to help fight infection