CML is yet another cancer of the white blood cells and is characterized by the increased and overproduction of myeloid cells in the bone marrow. CML has the "Philadelphia Chromosome" (Ph chromosome). Chromosomes are structures in the cells that contain genes. The Ph chromosome is created when chromosome 22 breaks off and attaches to the end of chromosome 9. A piece of chromosome 9 also breaks off and attaches to the end of chromosome 22. This creates the cancer gene.
CML can be caused by exposure to very high doses of radiation used to treat other cancers. However, most people treated for cancer with radiation do not develop CML, and most with CML were not exposed to high-dose radiation. CML is not a disease in which you can pass on to someone else.
Signs and Symptoms of CML
Those with CML may not have any symptoms at the time of their diagnosis. Their diagnosis is usually a byproduct of a routine checkup. CML signs and symptoms tend to develop gradually. Some symptoms of CML include:
- Shortness of breath doing usual daily activities
- Pale skin color
- Enlarged spleen (leaving a dragging feeling on upper left side of stomach)
- Night sweats
- Weight loss
- Inability to tolerate warm temperatures
Because many of these symptoms are similar to other illnesses, most people either go undiagnosed or misdiagnosed. The best way to determine the exactness of the disease is by means of a blood test.
Patients with accelerated phases of CML may even develop anemia, a blood condition in which the number of white cells are fluctuate. CML consists of three phases: chronic, accelerated and blast crisis.
Chronic Phase of CML
Majority of the patients are in the chronic phase of the disease upon diagnosis. CML symptoms in this phase are milder and their white blood cells can still fight infections. Patients who are diagnosed in their chronic phases can return to their usual activities once treated.
Accelerated Phase of CML
Patients with CML in the accelerated phase have a risk of developing anemia. Anemia is a blood disease in which the number of white cells may go up or down. The number of platelets (needed to create blood clots) may even drop, causing excessive bleeding or easy bruising. Blast cells may increase, leaving the spleen to swell. Blast cells are immature cells found in your bone marrow. If you are in the accelerated phase of your CML, you may feel ill.
Blast Crisis Phase of CML
Patients who are in the blast crisis phase of their CML have an increased number of blast cells in their bone marrow and blood. The number of red blood cells and platelets drop, leaving patients prone to infections or bleeding. If you are in the blast crisis phase of your CML, you may also feel tired and have shortness of breath, stomach or bone pain.
Treating your CML
In the chronic phase of your CML, treatment typically involves returning the number of blood cells to a normal level. At this point, your spleen should also return to its normal size and pain should no longer be felt in the abdomen. During your treatment for your chronic CML, you will not have infections or unusual bleeding.
Chronic CML patients will begin treatment with a drug called Gleevec, which controls the chronic phase. Gleevec has been FDA-approved since 2001 and has helped many CML patients control their chronic symptoms.
CML patients in the chronic phase also are treated with another FDA-approved drug called Sprycel. Sprycel has been approved in treating adults in all phases of CML and those who showed resistance or intolerance for prior CML therapy.
Recently approved, Tasigna is used to treat those that are newly diagnosed with chronic phase CML and was FDA-approved in October 2007. Tasigna has also been approved to treat accelerated phases of CML as well. Those who are given this drug were also resistant or intolerant to previous CML therapies.
All three drugs are taken by mouth. Most patients in the chronic phase of CML can typically continue their daily activities. The drug treatments are usually free of side effects. However, the drug therapy does not provide a cure for CML. Patients are still required to take routine blood tests and health checkups throughout their chronic phase treatment.
Accelerated Phase or Blast Crisis Phase
The goal during treating accelerated or blast crisis CML is to kill all cells that contain the cancer gene or to return the disease back to the chronic phase. In addition to the drugs administered to chronic CML patients, accelerated/blast crisis patients are also given drugs such as interferon, busulfan (Myleran), cytarabine (Cytosar-U) or hydroxyurea (Hydrea). These drugs can be used simultaneously with the chronic CML drugs and are all in pill form.
People who have very high counts of white blood cells at the time of diagnosis can reduce blood flow to the brain, lungs, eyes, as well as other parts of the body. Once the white blood cell count can be lowered, then oral drug therapy can be started. Excess white blood cells can be removed by a special machine. This process is called leukapheresis.
Side Effects Associated With Your Therapy
The side effects experienced during therapy either go away or become less noticeable over time. Management of side effects can be done without stopping the drug, possibly by lower dosages. It is encouraged that you talk to you doctor about the possible side effects of the drugs before beginning treatment.
Common side effects of Gleevec:
- Puffiness around the eyes
- Swelling from excess fluid in the body
- Possible loss of bone minerals
Common side effects of Sprycel:
- Too much chest fluid
- Low red cells, white cells and/or platelets
- Low calcium levels in blood
- Changes in liver function
- Edema (excess fluids in tissues)
Common side effects of Tasigna:
- Change in liver enzymes
- Change in pancreatic enzymes
- Low white cells and/or platelets
Possible side effect of Gleevec, Sprycel and Tasigna is the development of a heart condition called QT Prolongation. This is a heart rhythm condition in which your doctor needs to closely monitor throughout your treatment as needed. Your doctor should also provide you a list of medications to avoid.
Stem Cell Transplants for CML Patients
Stem cell transplantation is the only curative treatment for CML. It restores your defective bone marrow. The transplanted stem cells go from your blood to your marrow. Upon arrival at the marrow, the stem cells begin to start and produce a new batch of red cells, white cells and platelets—all of which were previously deficient. In order for the transplant to be successful, donor and recipient must be matched before surgery. Typically, your siblings will possible match.
Approximately 7 out of 10 people who have a stem cell transplant are cured of their CML. Despite its curative successes, stem cell transplants also have its high risks of complications. The decision to have a stem cell transplant depends on:
- Overall Health
- Donor cells/recipient match
- How you have responded to oral drug therapy
Donor Lymphocyte Infusion
CML patients whose disease returns after a stem cell transplant can be treated with Gleevec, Sprycel, Tasigna, or other CML drugs. A second transplant is always an option. Patients can be treated with a donor lymphocyte infusion, which is an infusion of white blood cells from the original stem donor.
It is possible to one day treat CML patients with vaccines and studies are currently being conducted. The use of vaccines can help treat (not prevent) CML by using your own immune cells to attach your CML cells.